Scalable Mechanisms for Rational Secret Sharing
Dani, Varsha; Saia, Jared
2012-01-01
We consider the classical secret sharing problem in the case where all agents are selfish but rational. In recent work, Kol and Naor show that, when there are two players, in the non-simultaneous communication model, i.e. when rushing is possible, there is no Nash equilibrium that ensures both players learn the secret. However, they describe a mechanism for this problem, for any number of players, that is an epsilon-Nash equilibrium, in that no player can gain more than epsilon utility by deviating from it. Unfortunately, the Kol and Naor mechanism, and, to the best of our knowledge, all previous mechanisms for this problem require each agent to send O(n) messages in expectation, where n is the number of agents. This may be problematic for some applications of rational secret sharing such as secure multi-party computation and simulation of a mediator. We address this issue by describing mechanisms for rational secret sharing that are designed for large n. Both of our results hold for n > 2, and are Nash equil...
Verifiable Rational Secret Sharing Scheme in Mobile Networks
En Zhang
2015-01-01
Full Text Available With the development of mobile network, lots of people now have access to mobile phones and the mobile networks give users ubiquitous connectivity. However, smart phones and tablets are poor in computational resources such as memory size, processor speed, and disk capacity. So far, all existing rational secret sharing schemes cannot be suitable for mobile networks. In this paper, we propose a verifiable rational secret sharing scheme in mobile networks. The scheme provides a noninteractively verifiable proof for the correctness of participants’ share and handshake protocol is not necessary; there is no need for certificate generation, propagation, and storage in the scheme, which is more suitable for devices with limited size and processing power; in the scheme, every participant uses her encryption on number of each round as the secret share and the dealer does not have to distribute any secret share; every participant cannot gain more by deviating the protocol, so rational participant has an incentive to abide by the protocol; finally, every participant can obtain the secret fairly (means that either everyone receives the secret, or else no one does in mobile networks. The scheme is coalition-resilient and the security of our scheme relies on a computational assumption.
Rational Secret Sharing over an Asynchronous Broadcast Channel with Information Theoretic Security
Moses, William K; 10.5121/ijnsa.2011.3601
2011-01-01
We consider the problem of rational secret sharing introduced by Halpern and Teague [1], where the players involved in secret sharing play only if it is to their advantage. This can be characterized in the form of preferences. Players would prefer to get the secret than to not get it and secondly with lesser preference, they would like as few other players to get the secret as possible. Several positive results have already been published to efficiently solve the problem of rational secret sharing but only a handful of papers have touched upon the use of an asynchronous broadcast channel. [2] used cryptographic primitives, [3] used an interactive dealer, and [4] used an honest minority of players in order to handle an asynchronous broadcast channel. In our paper, we propose an m-out-of-n rational secret sharing scheme which can function over an asynchronous broadcast channel without the use of cryptographic primitives and with a non-interactive dealer. This is possible because our scheme uses a small number, ...
The (2,2)Bayesian Rational Secret Sharing Sche me%（2，2）贝叶斯理性秘密共享方案
刘海; 彭长根; 田有亮; 吕桢; 刘荣飞
2014-01-01
在理性秘密共享协议中，自利性目标可能会驱使理性参与者偏离协议，从而影响协议的公平性。在（t， n）门限理性秘密共享方案中，其特殊情形（2，2）理性秘密共享方案的公平性较难实现。在同时考虑理性参与者的眼前利益和长远利益的基础上，基于不完全信息动态博弈模型，通过分析理性参与者在（2，2）秘密重构阶段可能采取的策略和信念系统，引入理性参与者的期望收益，研究了（2，2）理性秘密共享重构阶段的完美贝叶斯均衡问题。进一步结合机制设计理论中的VCG（Vickrey-Clarke-Groves）机制，设计激励相容的交互记录机制来约束理性参与者的行为，在不需要秘密分发者保持在线的情形下，提出一个适用于异步通信的公平的（2，2）理性秘密共享方案。%The rational secret sharing is an intersection direction between the traditional secret sharing and game theory .In the rational secret sharing scheme,the selfishness maybe impels rational players to deviate from the protocols so as to influence the fairness of scheme .In the existing threshold rational secret sharing schemes,the fairness of (2,2)rational secret sharing scheme, which is a special case,is hard to be realized,especially implementing on the asynchronous communication channel .To achieve fair-ness of (2,2)rational secret sharing over the asynchronous communication channel,this paper firstly analyzes rational players’utili-ty by simultaneously discussing their short-term interest and long-term interest .Then through illustrating rational players’available actions and belief systems,and computing their expected utilities with the dynamic games of incomplete information,the perfect Bayesian equilibrium for reconstruction phase of (2,2)rational secret sharing is studied.Furthermore,combining with the VCG (Vickrey-Clarke-Groves)mechanism of design theory,the incentive compatibility
Rational Secret Sharing Scheme Based on Reputation Mechanism%基于信誉机制的理性秘密共享方案
刘海; 彭长根; 吕桢; 刘荣飞
2012-01-01
理性秘密共享是博弈论与传统秘密共享相结合产生的新的研究方向.在理性秘密共享中,参与者从利益最大化的角度选择行为,在秘密重构阶段易出现“空威胁”和最后一轮不合作的问题.本文基于博弈论分析完全理性参与者在信誉机制下的行为偏好,采用激励相容原理,设计信誉惩罚机制,构建一个理性秘密共享方案.该方案通过信誉惩罚机制有效的约束完全理性参与者的行为,避免出现“空威胁”.并由信誉最高的参与者充当“可信中心”进行秘密重构,有效的解决在秘密重构阶段最后一轮各个参与者相互不合作的问题,防止参与者相互合谋的行为.%Rational secret sharing is a new hot topic, which is generated at the intersection of game theory and traditional secret sharing. The players choose actions by maximizing their payoff in the rational secret sharing. It is easy to cause the "empty threat" and non-cooperation in the last round of the secret reconstruction phase. This paper proposed a rational secret sharing scheme based on analyzing the preference of rational players in the reputation system using game theory, and designing the reputation punishment mechanism with the incentive compatibility. It effectively restricts the behavior of the completely rational players by reputation punishment mechanism, and avoids the "empty threat". Meanwhile, the secret was reconstructed by the highest reputation player that serves as " trusted center". The proposed scheme effectively solves the problem of non-cooperation and collusion of each player in the secret reconstruction phase.
Kaced, Tarik
2011-01-01
Splitting a secret s between several participants, we generate (for each value of s) shares for all participants. The goal: authorized groups of participants should be able to reconstruct the secret but forbidden ones get no information about it. In this paper we introduce several notions of non- perfect secret sharing, where some small information leak is permitted. We study its relation to the Kolmogorov complexity version of secret sharing (establishing some connection in both directions) and the effects of changing the secret size (showing that we can decrease the size of the secret and the information leak at the same time).
On Converting Secret Sharing Scheme to Visual Secret Sharing Scheme
Wang Daoshun
2010-01-01
Full Text Available Abstract Traditional Secret Sharing (SS schemes reconstruct secret exactly the same as the original one but involve complex computation. Visual Secret Sharing (VSS schemes decode the secret without computation, but each share is m times as big as the original and the quality of the reconstructed secret image is reduced. Probabilistic visual secret sharing (Prob.VSS schemes for a binary image use only one subpixel to share the secret image; however the probability of white pixels in a white area is higher than that in a black area in the reconstructed secret image. SS schemes, VSS schemes, and Prob. VSS schemes have various construction methods and advantages. This paper first presents an approach to convert (transform a -SS scheme to a -VSS scheme for greyscale images. The generation of the shadow images (shares is based on Boolean XOR operation. The secret image can be reconstructed directly by performing Boolean OR operation, as in most conventional VSS schemes. Its pixel expansion is significantly smaller than that of VSS schemes. The quality of the reconstructed images, measured by average contrast, is the same as VSS schemes. Then a novel matrix-concatenation approach is used to extend the greyscale -SS scheme to a more general case of greyscale -VSS scheme.
A New Rational Secret Sharing Based on Reputation Mechanism%一个新的基于信誉机制的理性秘密共享方案
徐志聘; 彭长根; 张豹
2012-01-01
针对秘密共享中理性参与者的效用函数难以刻画的问题,考虑参与者的信誉值构建了面向秘密共享的信誉机制;通过考虑理性参与者的长远利益和眼前利益,设计了更为合理的效用假设和效用函数,并以此为基础构建了一个新的基于信誉机制的理性秘密共享方案;最后通过博弈分析表明,在理性秘密共享重构阶段,合作是一个严格的占优策略,我们的方案可以有效地促进理性参与者进行合作,产生一个严格的纳什均衡.%In order to solve the problem that the secret sharing rational participants'utility function was difficult to describe, considered the participants'reputation value, a reputation mechanism for secret sharing was presented. Firstly. By considering the long-term interests and immediate interests of rational participants, a more reasonable utility assumption and utility function were designed, and then a new rational secret sharing scheme was constructed based on the reputation mechanism. Finally, the game analysis shows that the cooperation is a strictly dominant strategy in the rational secret sharing reconstruction phase, and the rational participants can be effective to promote cooperation in the proposed scheme, then a strict Nash equilibrium is produced.
Circular threshold quantum secret sharing
Yang Yu-Guang; Wen Qiao-Yan
2008-01-01
This paper proposes a circular threshold quantum secret sharing (TQSS) scheme with polarized single photons.A polarized single photon sequence runs circularly among any t or more of n parties and any t or more of n parties can reconstruct the secret key when they collaborate.It shows that entanglement is not necessary for quantum secret sharing.Moreover,the theoretic efficiency is improved to approach 100% as the single photons carrying the secret key are deterministically forwarded among any t or more of n parties,and each photon can carry one bit of information without quantum storage.This protocol is feasible with current technology.
An Image Secret Sharing Method
2006-07-01
M. E. Hellman, “On secret sharing systems,” vol. IT-29, no. 1, pp. 35–41, Jan. 1983. [10] K. Kurosawa , K. Okada, K. Sakano, W. Ogata, and S. Tsujii...Ed., Berlin, Germany, 1994, pp. 1–12. [14] W. Ogata and K. Kurosawa , “Some ba- sic properties of general nonperfect secret sharing schemes,” J.UCS
Secret sharing using biometric traits
Kholmatov, Alisher; Yanikoglu, Berrin; Savas, Erkay; Levi, Albert
2006-04-01
In biometric based authentication, biometric traits of a person are matched against his/her stored biometric profile and access is granted if there is sufficient match. However, there are other access scenarios, which require participation of multiple previously registered users for a successful authentication or to get an access grant for a certain entity. For instance, there are cryptographic constructs generally known as secret sharing schemes, where a secret is split into shares and distributed amongst participants in such a way that it is reconstructed/revealed only when the necessary number of share holders come together. The revealed secret can then be used for encryption or authentication (if the revealed key is verified against the previously registered value). In this work we propose a method for the biometric based secret sharing. Instead of splitting a secret amongst participants, as is done in cryptography, a single biometric construct is created using the biometric traits of the participants. During authentication, a valid cryptographic key is released out of the construct when the required number of genuine participants present their biometric traits.
基于中国剩余定理的可验证理性秘密共享方案%Verifiable rational secret sharing scheme based on Chinese remainder theorem
张利远; 张恩
2012-01-01
To address the problem that participant can not be added or deleted dynamically in rational secret sharing scheme so far, this paper proposed a dynamic rational secret sharing scheme which combined game theory with cryptography. The scheme based on Chinese remainder theorem, can add or delete the participant dynamically in the secret reconstruction phase. And it is verifiable by using the verifiable random function, and the cheat of participants cannot work. The participants did not know whether the current round was a testing round. And the gain of following the protocol was more than the gain of deviating, so rational player had an incentive to abide the protocol. Finally, every player could obtain the secret fairly. In addition, the scheme satisfied resilient equilibrium and could withstand the conspiracy attack.%针对目前理性秘密共享方案不能动态添加和删除参与者的问题,结合博弈论和密码学理论,提出一种动态理性秘密共享方案.方案基于中国剩余定理,在秘密重构过程,可以动态添加和删除参与者,另外方案采用可验证的随机函数,能检验参与者的欺骗行为.参与者不知当前轮是否是测试轮,偏离协议没有遵守协议的收益大,理性的参与者有动机遵守协议,最终每位参与者公平地得到秘密.方案不需要可信者参与,满足弹性均衡,能防止成员间的合谋攻击.
Secret sharing scheme with inherited characteristic
Ye Zhenjun; Meng Fanzhen
2006-01-01
To assure the shareholders can look for their "legal" attorneys to renew the secret, once the secret sharing scheme is initialized, a secret sharing scheme with inherited characteristic is constructed. In this scheme, each shareholder can produce a new share by his algorithm, which is equivalent to the primary one. Together with other shares, the primary secret can be renewed. Since this scheme is constructed not by replacing the primary share with a new share produced by the dealer in his primitive secret sharing scheme, so no matter how much shares the shareholder produces, these shares can not be gathered together to renew the secret in this scheme. Compared with the existing secret sharing schemes, this scheme provides more agility for the shareholders by investing each of them a function but not affect its security.
Cheater identifiable visual secret sharing scheme
Gan Zhi; Chen Kefei
2005-01-01
The visual secret sharing scheme proposed by Naor and Shamir provides a way to encrypt a secret black-white image into shares. A qualified group of participants can recover the secret message without using any cryptographic computation. But the original scheme can easily be corrupted by malicious participant. We propose an extension of VSS(visual secret sharing) to identify cheaters before the secret is recovered. Without the need for any additional information and cryptographic computation, every participant can verify the validity of shares of other participants, thus the security of VSS is enhanced.
Secret Sharing and Proactive Renewal of Shares in Hierarchical Groups
Naskar, Ruchira; 10.5121/ijcsit.2010.2312
2010-01-01
Secret sharing in user hierarchy represents a challenging area for research. Although a lot of work has already been done in this direc- tion, this paper presents a novel approach to share a secret among a hierarchy of users while overcoming the limitations of the already exist- ing mechanisms. Our work is based on traditional (k +1; n)-threshold secret sharing, which is secure as long as an adversary can compromise not more than k secret shares. But in real life it is often feasible for an adversary to obtain more than k shares over a long period of time. So, in our work we also present a way to overcome this vulnerability, while implementing our hierarchical secret sharing scheme. The use of Elliptic Curve Cryptography makes the computations easier and faster in our work.
Quantum secret sharing with minimized quantum communication
Fortescue, Ben; Gour, Gilad
2013-03-01
Standard techniques for sharing a quantum secret among multiple players (such that certain subsets of the players can recover the secret while others are denied all knowledge of the secret) require a large amount of quantum communication to distribute the secret, which is likely to be the most costly resource in any practical scheme. Two known methods for reducing this cost are the use of imperfect ``ramp'' secret sharing (in which security is sacrificed for efficiency) and classical encryption (in which certain elements of the players' shares consist of classical information only). We demonstrate how one may combine these methods to reduce the required quantum communication below what has been previously achieved, in some cases to a provable minimum, without any loss of security. The techniques involved are closely-related to the properties of stabilizer codes, and thus have strong potential for being adapted to a wide range of quantum secret sharing schemes.
Linear multi-secret sharing schemes
XIAO Liangliang; LIU Mulan
2005-01-01
In this paper the linear multi-secret sharing schemes are studied by using monotone span programs. A relation between computing monotone Boolean functions by using monotone span programs and realizing multi-access structures by using linear multisecret sharing schemes is shown. Furthermore, the concept of optimal linear multi-secret sharing scheme is presented and the several schemes are proved to be optimal.
DYNAMIC AND VERIFIABLE SECRET SHARING AMONG WEIGHTED PARTICIPANTS
Yanshuo ZHANG; Zhuojun LIU
2007-01-01
A secret sharing scheme permits a secret to be shared among participants in such a way that only qualified subsets of participants can recover the secret. Secret sharing is useful in management of cryptographic keys. Based on identity, we analyze the secret sharing scheme among weighted participants. Then we present a dynamic scheme about secret sharing among weighted participants. At last, we analyze the secret sharing scheme among weighted participants, which can make all weighted participants verifiable and dynamic.
Information Flow in Secret Sharing Protocols
Kashefi, Elham; Mhalla, Mehdi; Perdrix, Simon
2009-01-01
The entangled graph states have emerged as an elegant and powerful quantum resource, indeed almost all multiparty protocols can be written in terms of graph states including measurement based quantum computation (MBQC), error correction and secret sharing amongst others. In addition they are at the forefront in terms of implementations. As such they represent an excellent opportunity to move towards integrated protocols involving many of these elements. In this paper we look at expressing and extending graph state secret sharing and MBQC in a common framework and graphical language related to flow. We do so with two main contributions. First we express in entirely graphical terms which set of players can access which information in graph state secret sharing protocols. These succinct graphical descriptions of access allow us to take known results from graph theory to make statements on the generalisation of the previous schemes to present new secret sharing protocols. Second, we give a set of necessary condit...
On Secret Sharing with Nonlinear Product Reconstruction
Cascudo Pueyo, Ignacio; Cramer, Ronald; Mirandola, Diego
2015-01-01
Multiplicative linear secret sharing is a fundamental notion in the area of secure multiparty computation and, since recently, in the area of two-party cryptography as well. In a nutshell, this notion guarantees that the product of two secrets is obtained as a linear function of the vector consis...
On Secret Sharing with Nonlinear Product Reconstruction
Cascudo Pueyo, Ignacio; Cramer, Ronald; Mirandola, Diego
2015-01-01
Multiplicative linear secret sharing is a fundamental notion in the area of secure multiparty computation and, since recently, in the area of two-party cryptography as well. In a nutshell, this notion guarantees that the product of two secrets is obtained as a linear function of the vector consis...
Meaningful Share Generation for Increased Number of Secrets in Visual Secret-Sharing Scheme
Mustafa Ulutas
2010-01-01
Full Text Available This paper presents a new scheme for hiding two halftone secret images into two meaningful shares created from halftone cover images. Meaningful shares are more desirable than noise-like (meaningless shares in Visual Secret Sharing because they look natural and do not attract eavesdroppers' attention. Previous works in the field focus on either increasing number of secrets or creating meaningful shares for one secret image. The method outlined in this paper both increases the number of secrets and creates meaningful shares at the same time. While the contrast ratio of shares is equal to that of Extended Visual Cryptography, two secrets are encoded into two shares as opposed to one secret in the Extended Visual Cryptography. Any two natural-looking images can be used as cover unlike the Halftone Visual Cryptography method where one cover should be the negative of the other cover image and can only encode one secret. Effectiveness of the proposed method is verified by an experiment.
Secret Sharing of a Quantum State.
Lu, He; Zhang, Zhen; Chen, Luo-Kan; Li, Zheng-Da; Liu, Chang; Li, Li; Liu, Nai-Le; Ma, Xiongfeng; Chen, Yu-Ao; Pan, Jian-Wei
2016-07-15
Secret sharing of a quantum state, or quantum secret sharing, in which a dealer wants to share a certain amount of quantum information with a few players, has wide applications in quantum information. The critical criterion in a threshold secret sharing scheme is confidentiality: with less than the designated number of players, no information can be recovered. Furthermore, in a quantum scenario, one additional critical criterion exists: the capability of sharing entangled and unknown quantum information. Here, by employing a six-photon entangled state, we demonstrate a quantum threshold scheme, where the shared quantum secrecy can be efficiently reconstructed with a state fidelity as high as 93%. By observing that any one or two parties cannot recover the secrecy, we show that our scheme meets the confidentiality criterion. Meanwhile, we also demonstrate that entangled quantum information can be shared and recovered via our setting, which shows that our implemented scheme is fully quantum. Moreover, our experimental setup can be treated as a decoding circuit of the five-qubit quantum error-correcting code with two erasure errors.
Hash function based secret sharing scheme designs
Chum, Chi Sing
2011-01-01
Secret sharing schemes create an effective method to safeguard a secret by dividing it among several participants. By using hash functions and the herding hashes technique, we first set up a (t+1, n) threshold scheme which is perfect and ideal, and then extend it to schemes for any general access structure. The schemes can be further set up as proactive or verifiable if necessary. The setup and recovery of the secret is efficient due to the fast calculation of the hash function. The proposed scheme is flexible because of the use of existing hash functions.
Secret key generation via a modified quantum secret sharing protocol
Smith, A. M.; Evans, P. G.; Lawrie, B.; Legré, M.; Lougovski, P.; Ray, W.; Williams, B. P.; Qi, B.; Grice, W. P.
2015-05-01
We present and experimentally show a novel protocol for distributing secret information between two and only two parties in a N-party single-qubit Quantum Secret Sharing (QSS) system. We demonstrate this new algorithm with N = 3 active parties over ~6km of telecom. fiber. Our experimental device is based on the Clavis2 Quantum Key Distribution (QKD) system built by ID Quantique but is generalizable to any implementation. We show that any two out of the N parties can build secret keys based on partial information from each other and with collaboration from the remaining N - 2 parties. This algorithm allows for the creation of two-party secret keys were standard QSS does not and significantly reduces the number of resources needed to implement QKD on a highly connected network such as the electrical grid.
Secret Key Generation via a Modified Quantum Secret Sharing Protocol
Smith IV, Amos M [ORNL; Evans, Philip G [ORNL; Lawrie, Benjamin J [ORNL; Legre, Matthieu [ID Quantique, Inc.; Lougovski, Pavel [ORNL; Ray, William R [ORNL; Williams, Brian P [ORNL; Qi, Bing [ORNL; Grice, Warren P [ORNL
2015-01-01
We present and experimentally show a novel protocol for distributing secret information between two and only two parties in a N-party single-qubit Quantum Secret Sharing (QSS) system. We demonstrate this new algorithm with N = 3 active parties over 6km of telecom. ber. Our experimental device is based on the Clavis2 Quantum Key Distribution (QKD) system built by ID Quantique but is generalizable to any implementation. We show that any two out of the N parties can build secret keys based on partial information from each other and with collaboration from the remaining N > 2 parties. This algorithm allows for the creation of two-party secret keys were standard QSS does not and signicantly reduces the number of resources needed to implement QKD on a highly connected network such as the electrical grid.
A new scheme for quantum secret sharing
Bagherinezhad, S; Bagherinezhad, Saber; Karimipour, Vahid
2002-01-01
We introduce a protocol for quantum secret sharing based on reusable entangled states. The entangled state between the sender and the receiver acts only as a carrier and no measurement is performed on this shared state. Half of the sequence of bits can be retrieved independently and for the other half the receivers need each other's assistance. We also show that the protocol is completely safe against eavesdropping.
Secret Sharing Schemes and Advanced Encryption Standard
2015-09-01
Professor Bard xv Mansager, my academic advisor in the Department of Applied Mathematics. Bard was the one who reassured me that the Math Department...are obtained by an eavesdropper, and the eavesdropper decomposes the public shares into the generalized formula yi = (xi+α)k−b0 for secret recovery
Quantum Secret Sharing by applying Analytic Geometry
Liu, Ruilong
2010-01-01
In this paper, we investigate a novel $(2,2)$-threshold scheme and then generalize this to a $(n,n)$-threshold scheme for quantum secret sharing (QSS) which makes use of the fundamentals of Analytic Geometry. The dealer aptly selects GHZ states related to the coefficients which determine straight lines on a two-dimension plane. Then by computing each two of the lines intercept or not, we obtain a judging matrix whose rank can be used to determine the secret stored in entangled bits. Based on ...
Visual Secret Sharing Based Digital Image Watermarking
B. Surekha
2012-05-01
Full Text Available In this paper, a spatial domain image watermarking technique based on Visual Secret Sharing (VSS and unique statistical properties is proposed. A random looking image is generated during watermark hiding process and is secretly registered with an arbitrator for verification during conflicts. Another random looking image is generated during watermark revelation stage and is combined with the existing one, to recover the watermark. This whole process is done without altering the image to be protected and hence the quality of the cover image is high. When compared with similar existing techniques, the proposed technique has three main advantages: Provides greater convenience in carrying and storing the intermediate images called shares; Provides high security; Reduce tradeoff between spatial and frequency domain techniques in terms of robustness
Constructions for Anonymous Secret Sharing Schemes Using Combinatorial Designs
Ying-pu Deng; Li-feng Guo; Mu-lan Liu
2007-01-01
In an anonymous secret sharing scheme the secret can be reconstructed without knowledge of which participants hold which shares. In this paper some constructions of anonymous secret sharing schemes with 2 thresholds by using combinatorial designs are given. Let υ(t, ω, q) denote the minimum size of the set of shares of a perfect anonymous (t, ω) threshold secret sharing scheme with q secrets. In this paper we prove that υ(t, ω, q) = Θ(q) if t and ω are fixed and that the lower bound of the size of the set of shares in [4] is not optimal under certain condition.
Quantum Secret Sharing with Error Correction
Aziz Mouzali; Fatiha Merazka; Damian Markham
2012-01-01
We investigate in this work a quantum error correction on a five-qubits graph state used for secret sharing through five noisy channels. We describe the procedure for the five, seven and nine qubits codes. It is known that the three codes always allow error recovery if only one among the sent qubits is disturbed in the transmitting channel. However, if two qubits and more are disturbed, then the correction will depend on the used code. We compare in this paper the three codes by computing the average fidelity between the sent secret and that measured by the receivers. We will treat the case where, at most, two qubits are affected in each one of five depolarizing channels.
Verifiable Quantum ( k, n)-threshold Secret Key Sharing
Yang, Yu-Guang; Teng, Yi-Wei; Chai, Hai-Ping; Wen, Qiao-Yan
2011-03-01
Based on Lagrange interpolation formula and the post-verification mechanism, we show how to construct a verifiable quantum ( k, n) threshold secret key sharing scheme. Compared with the previous secret sharing protocols, ours has the merits: (i) it can resist the fraud of the dealer who generates and distributes fake shares among the participants during the secret distribution phase; Most importantly, (ii) It can check the cheating of the dishonest participant who provides a false share during the secret reconstruction phase such that the authorized group cannot recover the correct secret.
Ghany, Mohamed Abdel; Gamal, Hesham El
2008-01-01
This paper develops a novel framework for sharing secret keys using existing Automatic Repeat reQuest (ARQ) protocols. Our approach exploits the multi-path nature of the wireless environment to hide the key from passive eavesdroppers. The proposed framework does not assume the availability of any prior channel state information (CSI) and exploits only the one bit ACK/NACK feedback from the legitimate receiver. Compared with earlier approaches, the main innovation lies in the distribution of key bits among multiple ARQ frames. Interestingly, this idea allows for achieving a positive secrecy rate even when the eavesdropper experiences more favorable channel conditions, on average, than the legitimate receiver. In the sequel, we characterize the information theoretic limits of the proposed schemes, develop low complexity explicit implementations, and conclude with numerical results that validate our theoretical claims.
Quantum Secret Sharing Based on Chinese Remainder Theorem
SHI Rong-Hua; SU Qian; GUO Ying; LEE Moon Ho
2011-01-01
A novel quantum secret sharing (QSS) scheme is proposed on the basis of Chinese Remainder Theorem (CRT).In the scheme, the classical messages are mapped to secret sequences according to CRT equations, and distributed to different receivers by different dimensional superdense-coding respectively.CRT's secret sharing function, together with high-dimensional superdense-coding, provide convenience, security, and large capability quantum channel for secret distribution and recovering.Analysis shows the security of the scheme.
Shared Secrets versus Secrets Kept Private Are Linked to Better Adolescent Adjustment
Frijns, Tom; Finkenauer, Catrin; Keijsers, Loes
2013-01-01
It is a household notion that secrecy is bad while sharing is good. But what about shared secrets? The present research adopts a functional analysis of sharing secrets, arguing that it should negate harmful consequences generally associated with secrecy and serves important interpersonal functions in adolescence. A survey study among 790 Dutch…
Threshold Quantum Secret Sharing of Secure Direct Communication
LI Bao-Kui; YANG Yu-Guang; WEN Qiao-Yan
2009-01-01
We propose a (t, n)-threshold quantum secret sharing protocol of secure direct communication following some ideas of Zhang's protocol [Phys. Lett. A 342 (2005) 60] and Tokunaga et al.'s protocol [Phys. Rev. A 71 (2005) 012314]. The sender distributes the classical secret shares to his or her n agents and each agent owns a secret share in advance. The sender's secure direct communication message can be extracted by an agent subset by collaboration in such a way that at least t or more agents can obtain the secret message with the mutual assistances but any t - 1 or fewer agents cannot. In contrast to the previous multiparty quantum secret sharing protocols in which the sender's secret message can be recovered only if all the agents collaborate, our protocol is more practical and more flexible.
Continuous-variable quantum secret sharing by optical interferometry
Tyc, T; Tyc, Tomas; Sanders, Barry C.
2001-01-01
We develop the theory of continuous-variable quantum secret sharing and propose its interferometric realization using passive and active optical elements. In the ideal case of infinite squeezing, a fidelity ${\\cal F}$ of unity can be achieved with respect to reconstructing the quantum secret. We quantify the reduction in fidelity for the (2,3) threshold scheme due to finite squeezing and establish the condition for verifying that genuine quantum secret sharing has occurred.
Multi-group dynamic quantum secret sharing with single photons
Liu, Hongwei [School of Science and State Key Laboratory of Information Photonics and Optical Communications, Beijing University of Posts and Telecommunications, Beijing 100876 (China); Ma, Haiqiang, E-mail: hqma@bupt.edu.cn [School of Science and State Key Laboratory of Information Photonics and Optical Communications, Beijing University of Posts and Telecommunications, Beijing 100876 (China); Wei, Kejin [School of Science and State Key Laboratory of Information Photonics and Optical Communications, Beijing University of Posts and Telecommunications, Beijing 100876 (China); Yang, Xiuqing [School of Science, Beijing Jiaotong University, Beijing 100044 (China); Qu, Wenxiu; Dou, Tianqi; Chen, Yitian; Li, Ruixue; Zhu, Wu [School of Science and State Key Laboratory of Information Photonics and Optical Communications, Beijing University of Posts and Telecommunications, Beijing 100876 (China)
2016-07-15
In this letter, we propose a novel scheme for the realization of single-photon dynamic quantum secret sharing between a boss and three dynamic agent groups. In our system, the boss can not only choose one of these three groups to share the secret with, but also can share two sets of independent keys with two groups without redistribution. Furthermore, the security of communication is enhanced by using a control mode. Compared with previous schemes, our scheme is more flexible and will contribute to a practical application. - Highlights: • A multi-group dynamic quantum secret sharing with single photons scheme is proposed. • Any one of the groups can be chosen to share secret through controlling the polarization of photons. • Two sets of keys can be shared simultaneously without redistribution.
Information-Theoretic Secure Verifiable Secret Sharing over RSA Modulus
QIU Gang; WANG Hong; WEI Shimin; XIAO Guozhen
2006-01-01
The well-known non-interactive and information-theoretic secure verifiable secret sharing scheme presented by Pedersen is over a large prime. In this paper, we construct a novel non-interactive and information-theoretic verifiable secret sharing over RSA (Rivest,Shamir,Adleman) modulus and give the rigorous security proof. It is shown how to distribute a secret among a group such that any set of k parties get no information about the secret. The presented scheme is generally applied to constructions of secure distributed multiplication and threshold or forward-secure signature protocols.
Continuous Variables (2,3) Threshold Quantum Secret Sharing Schemes
Lance, A M; Bowen, W P; Tyc, T; Sanders, B C; Lam, P K
2003-01-01
We present two experimental schemes to perform continuous variable (2,3) threshold quantum secret sharing on the quadratures amplitudes of bright light beams. Both schemes require a pair of entangled light beams. The first scheme utilizes two phase sensitive optical amplifiers, whilst the second uses an electro-optic feedforward loop for the reconstruction of the secret. We examine the efficacy of quantum secret sharing in terms of fidelity, as well as the signal transfer coefficients and the conditional variances of the reconstructed output state. We show that both schemes in the ideal case yield perfect secret reconstruction.
Multiparty Quantum Secret Sharing of Quantum States with Quantum Registers
GUO Ying; ZENG Gui-Hua; CHEN Zhi-Gang
2007-01-01
A quantum secret sharing scheme is proposed by making use of quantum registers.In the proposed scheme,secret message state is encoded into multipartite entangled states.Several identical multi-particle entanglement states are generated and each particle of the entanglement state is filled in different quantum registers which act as shares of the secret message.Two modes,j.e.the detecting mode and the message mode,are employed so that the eavesdropping can be detected easily and the secret message may be recovered.The seeurity analysis shows that the proposed scheme is secure against eavesdropping of eavesdropper and cheating of participants.
How to secretly share the treasure map of the captain?
Islam, N.; Puech, W.; Brouzet, R.
2010-01-01
In this paper we present a new approach for sharing a secret image between l users exploiting additive homomorphic property of Paillier algorithm. With a traditional approach, when a dealer wants to share an image between l players, the secret image must be sequentially encrypted l + 1 times using l + 1 keys (secret or public keys). When the dealer and the l players want to extract the secret image, they must decrypt sequentially, keeping the same order of the encryption step, by using l + 1 keys (secret or private). With the proposed approach, during the encryption step, each player encrypts his own secret image using the same public key given by the dealer, the dealer encrypts the secret image to be shared with the same key and then the l secret encrypted images plus the encrypted image to be shared are multiplied between them to get a scrambled image. After this step, the dealer can securely use the private key to decrypt this scrambled image to get a new scrambled image which corresponds to the addition of the l + 1 original images because of the additive homomorphic property of Paillier algorithm. When the l players want to extract the secret image, they do not need the dealer and to use keys. Indeed, with our approach, to extract the secret image, the l players need only to subtract their own secret image from the scrambled image. In this paper we illustrate our approach with an example of a captain who wants to share a secret treasure map between l pirates. Experimental results and security analysis show the effectiveness of the proposed scheme.
Leakproof secret sharing protocols with applications to group identification scheme
TANG ChunMing; GAO ShuHong
2012-01-01
In a traditional (t,n)-threshold secret sharing scheme,t or more honest participants can reconstruct the secret K.In the reconstruction process,the individual shares and the secret key K are revealed,hence K is shared once only. In this paper,we firstly give the definition of leakproof secret sharing scheme which is composed of a distribution protocol and a proof protocol,then propose two leakproof secret sharing protocols,a computationally secure protocol and an information-theoretically secure protocol.In our protocols,t or more participants can jointly prove that they hold the secret K by using a multi-prover zero-knowledge argument of knowledge.As a result,the secret K will be shared for as many times as desired.Furthermore,each participant can detect the dealer in the distribution protocol from cheating,and any verifier can prevent non-qualified set of participants in proof protocol from cheating.As an example of the practical impact of our work we use our techniques to construct group identification schemes with zero-knowledge.
Dynamic Vector Space Secret Sharing Based on Certificates
XU Chunxiang; LI Jiajia; LIU Dongsu
2006-01-01
A vector space secret sharing scheme based on certificates is proposed in this paper. The difficulties of solving discrete logarithm assure confidential information's security, and the use of each participant's certificate makes the dealer have no need to transfer secret information to the participants. The proposed scheme is dynamic. It can effectively check cheaters and does not have secure channel requirements.
Multiparty simultaneous quantum identity authentication with secret sharing
2008-01-01
Two multiparty simultaneous quantum identity authentication (MSQIA) protocols based on secret sharing are presented. All the users can be authenticated by a trusted third party (TTP) simultaneously. In the first protocol,the TTP shares a random key K with all the users using quantum secret sharing. The ith share acts as the authentication key of the ith user. When it is necessary to perform MSQIA,the TTP generates a random number R secretly and sends a sequence of single photons encoded with K and R to all the users. According to his share,each user performs the corresponding unitary operations on the single photon sequence sequentially. At last,the TTP can judge whether the impersonator exists. The sec-ond protocol is a modified version with a circular structure. The two protocols can be efficiently used for MSQIA in a network. They are feasible with current technol-ogy.
Multiparty simultaneous quantum identity authentication with secret sharing
YANG YuGuang; WEN QiaoYan; ZHANG Xing
2008-01-01
Two multiparty simultaneous quantum identity authentication (MSQIA) protocols based on secret sharing are presented.All the users can be authenticated by a trusted third party (TTP) simultaneously.In the first protocol, the TTP shares a random key K with all the users using quantum secret sharing.The ith share acts as the authentication key of the ith user.When it is necessary to perform MSQIA, the TTP generates a random number R secretly and sends a sequence of single photons encoded with K and R to all the users.According to his share, each user performs the corresponding unitary operations on the single photon sequence sequentially.At last, the TTP can judge whether the impersonator exists.The sec-ond protocol is a modified version with a circular structure.The two protocols can be efficiently used for MSQIA in a network.They are feasible with current technol-ogy.
Quantum Secret Sharing with Two-Particle Entangled States
LIU Wei-Tao; LIANG Lin-Mei; LI Cheng-Zu; YUAN Jian-Min
2006-01-01
We present a new protocol for the quantum secret sharing (QSS) task among multiparties with two-particle entangled states. In our scheme, the secret is split among a number of participating partners and the reconstruction requires collaboration of all the authorized partners. Instead of multiparticle Greenberger-Horne-Zeilinger states,only two-particle entangled states are employed in this scheme. By local operations and individual measurements on either of the two entangled particles, each authorized partner obtains a sequence of secret bits shared with other authorized partners. This protocol can be experimentally realized using only linear optical elements and simple entanglement source. It is scalable in practice.
SSDLP: Sharing Secret Data between Leader and Participant
Hazem Al-Najjar
2014-01-01
Full Text Available This paper investigates the problem of sharing the secret document containing a secret data between leader and participant(s depending on specific conditions and rules. The participant(s can retrieve part of the secret document but will not be able to retrieve any secret data without the leader. At the same time, the leader may have a little information about the secret document but cannot retrieve the secret data and the secret document without cooperating with participant(s. To evaluate the proposed model and the system efficiency, four tests are suggested, which are concatenation and sharing data test, leader visual test, information entropy analysis, and correlation analysis. Results show that the proposed model is efficient in sharing the data between the leader and participant(s and the model can achieve our concept of the data sharing between leader and participant(s. However, by analyzing the proposed model using numerical tests and visual tests, the results show that the visual tests will not give attackers useful information about the original data, while the numerical tests show that the entropy attacks are not possible and the correlation between the adjacent pixels will not give useful information. Finally, the results show that the proposed model is strong against different types of attacks.
Secret Sharing and Secure Computing from Monotone Formulae
Damgård, Ivan Bjerre; Kölker, Jonas; Miltersen, Peter Bro
2012-01-01
We present a construction of log-depth formulae for various threshold functions based on atomic threshold gates of constant size. From this, we build a new family of linear secret sharing schemes that are multiplicative, scale well as the number of players increases and allows to raise a shared...
Cropping and noise resilient steganography algorithm using secret image sharing
Juarez-Sandoval, Oswaldo; Fierro-Radilla, Atoany; Espejel-Trujillo, Angelina; Nakano-Miyatake, Mariko; Perez-Meana, Hector
2015-03-01
This paper proposes an image steganography scheme, in which a secret image is hidden into a cover image using a secret image sharing (SIS) scheme. Taking advantage of the fault tolerant property of the (k,n)-threshold SIS, where using any k of n shares (k≤n), the secret data can be recovered without any ambiguity, the proposed steganography algorithm becomes resilient to cropping and impulsive noise contamination. Among many SIS schemes proposed until now, Lin and Chan's scheme is selected as SIS, due to its lossless recovery capability of a large amount of secret data. The proposed scheme is evaluated from several points of view, such as imperceptibility of the stegoimage respect to its original cover image, robustness of hidden data to cropping operation and impulsive noise contamination. The evaluation results show a high quality of the extracted secret image from the stegoimage when it suffered more than 20% cropping or high density noise contamination.
Multiparty Quantum Secret Sharing of Quantum States Using Entanglement States
GUO Ying; HUANG Da-Zu; ZENG Gui-Hua; LEE Moon Ho
2008-01-01
A multi-partite-controlled quantum secret sharing scheme using several non-orthogonal entanglement states is presented with unconditional security.In this scheme,the participants share the secret quantum state by exchanging the secret polarization angles of the disordered travel particles.The security of the secret quantum state is also guaranteed by the non-orthogonal multi-partite-controlled entanglement states,the participants'secret polarizations,and the disorder of the travelling particles.Moreover,the present scheme is secure against the particle-number splitting attack and the intercept-and-resend attack.It may be still secure even if the distributed quantum state is embedded in a not-so-weak coherent-state pulse.
Efficient sharing of a continuous-variable quantum secret
Tyc, T; Sanders, B C; Tyc, Tomas; Rowe, David J.; Sanders, Barry C.
2003-01-01
We propose an efficient scheme for sharing a continuous variable quantum secret using passive optical interferometry and squeezers: this efficiency is achieved by showing that a maximum of two squeezers is required to replicate the secret state, and we obtain the cheapest configuration in terms of total squeezing cost. Squeezing is a cost for the dealer of the secret as well as for the receivers, and we quantify limitations to the fidelity of the replicated secret state in terms of the squeezing employed by the dealer.
Multi-group dynamic quantum secret sharing with single photons
Liu, Hongwei; Ma, Haiqiang; Wei, Kejin; Yang, Xiuqing; Qu, Wenxiu; Dou, Tianqi; Chen, Yitian; Li, Ruixue; Zhu, Wu
2016-07-01
In this letter, we propose a novel scheme for the realization of single-photon dynamic quantum secret sharing between a boss and three dynamic agent groups. In our system, the boss can not only choose one of these three groups to share the secret with, but also can share two sets of independent keys with two groups without redistribution. Furthermore, the security of communication is enhanced by using a control mode. Compared with previous schemes, our scheme is more flexible and will contribute to a practical application.
(N, N Secret Color Image Sharing Scheme with Dynamic Group
Mohamed Fathimal. P
2015-06-01
Full Text Available In recent years, secure information sharing has become a top requirement for many applications such as banking and military. Secret Sharing is an effective method to improve security of data. Secret Sharing helps to avoid storing data at a single point through dividing and distributing "shares" of secrets and recovering it later with no loss of original quality. This paper proposes a new Secret Sharing scheme for secure transmission of color images. The key features of this scheme are better visual quality of the recovered image with no pixel expansion, eliminating half toning of color images, eliminating the need for code book to decrypt images since reconstruction is done through XOR ing of all images and non-requirement of regeneration of shares for addition or deletion of users leading to less computational complexity. Besides these advantages, this scheme also helps to renew shares periodically and is highly beneficial in applications where data has to be stored securely in a database.
Special secret sharing scheme with the function of assignment
无
2005-01-01
A concept of secret sharing scheme with the function of assignment is proposed. It provides great capabilities for many practical applications. In this scheme, the dealer can randomly assign one or more than one participant to get the secret at any time, but these participants can get nothing about the secret before that moment. At the same time, the other participants cannot get any-thing about the secret by stealing the secret value when it is transferred. However, if the dealer is lost, a certain number or more participants of them can reconstruct the secret by cooperating. In order to clear this concept, an illustrating scheme with geometry method and a practical scheme with algebra method is given.
A Homomorphic Method for Sharing Secret Images
Islam, Naveed; Puech, William; Brouzet, Robert
In this paper, we present a new method for sharing images between two parties exploiting homomorphic property of public key cryptosystem. With our method, we show that it is possible to multiply two encrypted images, to decrypt the resulted image and after to extract and reconstruct one of the two original images if the second original image is available. Indeed, extraction and reconstruction of original image at the receiving end is done with the help of carrier image. Experimental results and security analysis show the effectiveness of the proposed scheme.
Secret Sharing over Fast-Fading MIMO Wiretap Channels
Bloch Matthieu
2009-01-01
Full Text Available Secret sharing over the fast-fading MIMO wiretap channel is considered. A source and a destination try to share secret information over a fast-fading MIMO channel in the presence of an eavesdropper who also makes channel observations that are different from but correlated to those made by the destination. An interactive, authenticated public channel with unlimited capacity is available to the source and destination for the secret sharing process. This situation is a special case of the "channel model with wiretapper" considered by Ahlswede and Csiszár. An extension of their result to continuous channel alphabets is employed to evaluate the key capacity of the fast-fading MIMO wiretap channel. The effects of spatial dimensionality provided by the use of multiple antennas at the source, destination, and eavesdropper are then investigated.
Participant attack on quantum secret sharing based on entanglement swapping
Song Ting-Ting; Zhang Jie; Gao Fei; Wen Qiao-Yan; Zhu Fu-Chen
2009-01-01
The security of quantum secret sharing based on entanglement swapping is revisited and a participant attack is presented.In this attack two dishonest agents together can illegally recover the secret quantum state without the help of any other controller,and it will not be detected by any othcr users.Furthermore,by modifying the distribution process of particles and adding a detection step after each distribution process,we propose an improved protocol which can resist this kind of attack.
Security of Linear Secret-Sharing Schemes Against Mass Surveillance
Giacomelli, Irene; Olimid, Ruxandra; Ranellucci, Samuel
2015-01-01
Following the line of work presented recently by Bellare, Paterson and Rogaway, we formalize and investigate the resistance of linear secret-sharing schemes to mass surveillance. This primitive is widely used to design IT systems in the modern computer world, and often it is implemented by a prop......Following the line of work presented recently by Bellare, Paterson and Rogaway, we formalize and investigate the resistance of linear secret-sharing schemes to mass surveillance. This primitive is widely used to design IT systems in the modern computer world, and often it is implemented...
Quantum secret sharing using the d-dimensional GHZ state
Bai, Chen-Ming; Li, Zhi-Hui; Xu, Ting-Ting; Li, Yong-Ming
2017-03-01
We propose a quantum secret sharing scheme that uses an orthogonal pair of n-qudit GHZ states and local distinguishability. In the proposed protocol, the participants use an X-basis measurement and classical communication to distinguish between the two orthogonal states and reconstruct the original secret. We also present (2, n)-threshold and generalized restricted (2, n)-threshold schemes that enable any two cooperating players from two disjoint groups to always reconstruct the secret. Compared to the existing scheme by Rahaman and Parker (Phys Rev A 91:022330, 2015), the proposed scheme is more general and the access structure contains more authorized sets.
Security of Linear Secret-Sharing Schemes Against Mass Surveillance
Giacomelli, Irene; Olimid, Ruxandra; Ranellucci, Samuel
2015-01-01
Following the line of work presented recently by Bellare, Paterson and Rogaway, we formalize and investigate the resistance of linear secret-sharing schemes to mass surveillance. This primitive is widely used to design IT systems in the modern computer world, and often it is implemented by a prop...... there exists an undetectable subversion of it that efficiently allows surveillance. Second, we formalize the security notion that assures that a sharing scheme is secure against ASAs and construct the first sharing scheme that meets this notion....... by a proprietary code that the provider (“big brother”) could manipulate to covertly violate the privacy of the users (by implementing Algorithm-Substitution Attacks or ASAs). First, we formalize the security notion that expresses the goal of big brother and prove that for any linear secret-sharing scheme...
Experimental demonstration of graph-state quantum secret sharing
Bell, B A; Herrera-Martí, D A; Marin, A; Wadsworth, W J; Rarity, J G; Tame, M S
2014-01-01
Distributed quantum communication and quantum computing offer many new opportunities for quantum information processing. Here networks based on highly nonlocal quantum resources with complex entanglement structures have been proposed for distributing, sharing and processing quantum information. Graph states in particular have emerged as powerful resources for such tasks using measurement-based techniques. We report an experimental demonstration of graph-state quantum secret sharing, an important primitive for a quantum network. We use an all-optical setup to encode quantum information into photons representing a five-qubit graph state. We are able to reliably encode, distribute and share quantum information between four parties. In our experiment we demonstrate the integration of three distinct secret sharing protocols, which allow for security and protocol parameters not possible with any single protocol alone. Our results show that graph states are a promising approach for sophisticated multi-layered protoc...
Optimal Black-Box Secret Sharing over Arbitrary Abelian Groups
Cramer, Ronald; Fehr, Serge
2002-01-01
. A recent example is secure general multi-party computation over black-box rings. In 1994 Desmedt and Frankel have proposed an elegant approach to the black-box secret sharing problem based in part on polynomial interpolation over cyclotomic number fields. For arbitrary given T t,n with 0
Universal Three-Party Quantum Secret Sharing Against Collective Noise
YANG Yu-Guang; WANG Yuan; TENG Yi-Wei; WEN Qiao-Yan
2011-01-01
we present a robust and universal quantum secret sharing protocol with four-qubit decoherence-free (DF) states against collective noise. The transmission's safety is ensured by the nonorthogonality of the noiseless states traveling on the quantum channel. Although this scheme uses entangled states for encoding, only single-particle product measurements are required.
Scheme for implementing quantum secret sharing via cavity QED
Chen Zhi-Hua; Lin Xiu-Min
2005-01-01
An experimentally feasible scheme for implementing quantum secret sharing via cavity quantum electrodynamics (QED) is proposed. The scheme requires the large detuning of the cavity field from the atomic transition, the cavity is only virtually excited, thus the requirement on the quality factor of the cavity is greatly loosened.
Entanglement Swapping of Generalized Cat States and Secret Sharing
Karimipour, V; Bahraminasab, A; Karimipour, Vahid; Bagherinezhad, Saber; Bahraminasab, Alireza
2002-01-01
We introduce generalized cat states for d-level systems and obtain concise formulas for their entanglement swapping with generalized Bell states. We then use this to provide both a generalization to the d-level case and a transparent proof of validity for an already proposed protocol of secret sharing based on entanglement swapping
Multiparty quantum secret sharing of classical and quantum messages
CHEN Pan; DENG Fuguo; LONG Guilu
2007-01-01
A scheme for multiparty quantum secret sharing of classical and quantum messages is proposed by using entanglement swapping. This scheme can distribute not only the classical information but also the quantum information between N agents. The security of our scheme is also confirmed.
Combination of Sharing Matrix and Image Encryption for Lossless $(k,n)$ -Secret Image Sharing.
Bao, Long; Yi, Shuang; Zhou, Yicong
2017-12-01
This paper first introduces a (k,n) -sharing matrix S((k, n)) and its generation algorithm. Mathematical analysis is provided to show its potential for secret image sharing. Combining sharing matrix with image encryption, we further propose a lossless (k,n) -secret image sharing scheme (SMIE-SIS). Only with no less than k shares, all the ciphertext information and security key can be reconstructed, which results in a lossless recovery of original information. This can be proved by the correctness and security analysis. Performance evaluation and security analysis demonstrate that the proposed SMIE-SIS with arbitrary settings of k and n has at least five advantages: 1) it is able to fully recover the original image without any distortion; 2) it has much lower pixel expansion than many existing methods; 3) its computation cost is much lower than the polynomial-based secret image sharing methods; 4) it is able to verify and detect a fake share; and 5) even using the same original image with the same initial settings of parameters, every execution of SMIE-SIS is able to generate completely different secret shares that are unpredictable and non-repetitive. This property offers SMIE-SIS a high level of security to withstand many different attacks.
Quantum secret sharing based on quantum error-correcting codes
Zhang Zu-Rong; Liu Wei-Tao; Li Cheng-Zu
2011-01-01
Quantum secret sharing(QSS) is a procedure of sharing classical information or quantum information by using quantum states. This paper presents how to use a [2k - 1,1, k] quantum error-correcting code (QECC) to implement a quantum (k, 2k - 1) threshold scheme. It also takes advantage of classical enhancement of the [2k - 1, l,k] QECC to establish a QSS scheme which can share classical information and quantum information simultaneously. Because information is encoded into QECC, these schemes can prevent intercept-resend attacks and be implemented on some noisy channels.
Security of Linear Secret-Sharing Schemes Against Mass Surveillance
Giacomelli, Irene; Olimid, Ruxandra; Ranellucci, Samuel
2015-01-01
Following the line of work presented recently by Bellare, Paterson and Rogaway, we formalize and investigate the resistance of linear secret-sharing schemes to mass surveillance. This primitive is widely used to design IT systems in the modern computer world, and often it is implemented by a prop......Following the line of work presented recently by Bellare, Paterson and Rogaway, we formalize and investigate the resistance of linear secret-sharing schemes to mass surveillance. This primitive is widely used to design IT systems in the modern computer world, and often it is implemented...... by a proprietary code that the provider (“big brother”) could manipulate to covertly violate the privacy of the users (by implementing Algorithm-Substitution Attacks or ASAs). First, we formalize the security notion that expresses the goal of big brother and prove that for any linear secret-sharing scheme...... there exists an undetectable subversion of it that efficiently allows surveillance. Second, we formalize the security notion that assures that a sharing scheme is secure against ASAs and construct the first sharing scheme that meets this notion....
A Novel Approach for Verifiable Secret Sharing by using a One Way Hash Function
Parmar, Keyur
2012-01-01
Threshold secret sharing schemes do not prevent any malicious behavior of the dealer or shareholders and so we need verifiable secret sharing, to detect and identify the cheaters, to achieve fair reconstruction of a secret. The problem of verifiable secret sharing is to verify the shares distributed by the dealer. A novel approach for verifiable secret sharing is presented in this paper where both the dealer and shareholders are not assumed to be honest. In this paper, we extend the term verifiable secret sharing to verify the shares, distributed by a dealer as well as shares submitted by shareholders for secret reconstruction, and to verify the reconstructed secret. Our proposed scheme uses a one way hash function and probabilistic homomorphic encryption function to provide verifiability and fair reconstruction of a secret.
Multiparty Quantum Secret Sharing Using Quantum Fourier Transform
HUANG Da-Zu; CHEN Zhi-Gang; GUO Ying
2009-01-01
A (n, n )-threshold scheme of multiparty quantum secret sharing of classical or quantum message is proposed based on the discrete quantum Fourier transform.In our proposed scheme, the secret message, which is encoded by using the forward quantum Fourier transform and decoded by using the reverse, is split and shared in such a way that it can be reconstructed among them only if all the participants work in concert.Furthermore, we also discuss how this protocol must be carefully designed for correcting errors and checking eavesdropping or a dishonest participant.Security analysis shows that our scheme is secure.Also, this scheme has an advantage that it is completely compatible with quantum computation and easier to realize in the distributed quantum secure computation.
An Advanced Threshold Secret Sharing Scheme for Identifying Cheaters
XIE Shu-cui; ZHANG Jian-zhong
2003-01-01
In this paper an advanced threshold secret sharing scheme for identifying cheaters is proposed by using authentication codes. The performance of the scheme is discussed. The results show that in the scheme the valid shareholders can not only identify the impersonation of an adversary, but also detect cheating of some valid shareholders. In particular one honest shareholder is able to detect cheating of other participants forming a collection, and the information rate of the scheme is higher than that of others.
Experimental quantum secret sharing and third-man quantum cryptography.
Chen, Yu-Ao; Zhang, An-Ning; Zhao, Zhi; Zhou, Xiao-Qi; Lu, Chao-Yang; Peng, Cheng-Zhi; Yang, Tao; Pan, Jian-Wei
2005-11-11
Quantum secret sharing (QSS) and third-man quantum cryptography (TQC) are essential for advanced quantum communication; however, the low intensity and fragility of the multiphoton entanglement source in previous experiments have made their realization an extreme experimental challenge. Here, we develop and exploit an ultrastable high intensity source of four-photon entanglement to report an experimental realization of QSS and TQC. The technology developed in our experiment will be important for future multiparty quantum communication.
How to Split a Shared Secret into Shared Bits in Constant-Round
Damgård, Ivan Bjerre; Fitzi, Matthias; Nielsen, Jesper Buus
We show that if a set of players hold shares of a value $a\\in Z_p$ for some prime $p$ (where the set of shares is written $[a]_p$), it is possible to compute, in constant round and with unconditional security, sharings of the bits of $a$, i.e.~compute sharings $[a_0]_p, \\ldots, [a_{l-1}]_p......$ such that $l = \\lceil \\log_2(p) \\rceil$, $a_0, \\ldots, a_{l-1} \\in \\{0,1\\}$ and $a = \\sum_{i=0}^{l-1} a_i 2^i$. Our protocol is secure against active adversaries and works for any linear secret sharing scheme with a multiplication protocol. This result immediately implies solutions to other long-standing open...... problems, such as constant-round and unconditionally secure protocols for comparing shared numbers and deciding whether a shared number is zero. The complexity of our protocol is $O(l \\log(l))$ invocations of the multiplication protocol for the underlying secret sharing scheme, carried out in $O(1)$....
Eavesdropping in a quantum secret sharing protocol based on Grover algorithm and its solution
无
2010-01-01
A detailed analysis has showed that the quantum secret sharing protocol based on the Grover algorithm (Phys Rev A, 2003, 68: 022306) is insecure. A dishonest receiver may obtain the full information without being detected. A quantum secret-sharing protocol is presents here, which mends the security loophole of the original secret-sharing protocol, and doubles the information capacity.
On codes, matroids and secure computation from linear secret sharing schemes
Cramer, R.J.F.; Daza, V.; Gracia, J.L.; Jimenez Urroz, J.; Leander, G.; Marti-Farre, J.; Padro, C.
2008-01-01
Error-correcting codes and matroids have been widely used in the study of ordinary secret sharing schemes. In this paper, the connections between codes, matroids, and a special class of secret sharing schemes, namely, multiplicative linear secret sharing schemes (LSSSs), are studied. Such schemes ar
Protection of multicast scalable video by secret sharing: simulation results
Eskicioglu, Ahmet M.; Dexter, Scott; Delp, Edward J., III
2003-06-01
Security is an increasingly important attribute for multimedia applications that require prevention of unauthorized access to copyrighted data. Two approaches have been used to protect scalable video content in distribution: Partial encryption and progressive encryption. Partial encryption provides protection for only selected portions of the video. Progressive encryption allows transcoding with simple packet truncation, and eliminates the need to decrypt the video packets at intermediate network nodes with low complexity. Centralized Key Management with Secret Sharing (CKMSS) is a recent approach in which the group manager assigns unique secret shares to the nodes in the hierarchical key distribution tree. It allows the reconstruction of different keys by communicating different activating shares for the same prepositioned information. Once the group key is established, it is used until a member joins/leaves the multicast group or periodic rekeying occurs. In this paper, we will present simulation results regarding the communication and processing requirements of the CKMSS scheme applied to scalable video. In particular, we have measured the rekey message size and the processing time needed by the server for each join/leave request and periodic rekey event.
A Secret Image Sharing Method Using Integer Wavelet Transform
Li Ching-Chung
2007-01-01
Full Text Available A new image sharing method, based on the reversible integer-to-integer (ITI wavelet transform and Shamir's threshold scheme is presented, that provides highly compact shadows for real-time progressive transmission. This method, working in the wavelet domain, processes the transform coefficients in each subband, divides each of the resulting combination coefficients into shadows, and allows recovery of the complete secret image by using any or more shadows . We take advantages of properties of the wavelet transform multiresolution representation, such as coefficient magnitude decay and excellent energy compaction, to design combination procedures for the transform coefficients and processing sequences in wavelet subbands such that small shadows for real-time progressive transmission are obtained. Experimental results demonstrate that the proposed method yields small shadow images and has the capabilities of real-time progressive transmission and perfect reconstruction of secret images.
Attack on the Enhanced Multiparty Quantum Secret Sharing
杨帅; 陈秀波; 杨义先
2012-01-01
Recently, Gao et al.＇s [Commun. Theor. Phys. 52 （2009） 421] multiparty quantum secret sharing （MQSS） protocol with two-photon three-dimensional Bell states was enhanced by Hwang et al. [Commun. Theor. Phys. 56 （2011） 79]. The improved protocol removes some unnecessary unitary operations, devices, and transmissions by the technique of decoy single photons and careful modification. However, in this paper, we investigate the security of the improved protocol and find it is insecure. The eavesdropper can steal all Alice＇s secret information. Furthermore, a feasible modification to remedy the security loophole is put forward. Our improved protocol provides a basic method to modify a kind of MQSS protocols which cannot resist the collusion attack.
An efficient quantum secret sharing protocol with orthogonal product states
2007-01-01
An efficient quantum secret sharing protocol with orthogonal product states in the 33 Hilbert space is presented. The particles in the orthogonal product states form two particle sequences. One sequence is sent to Bob and the other is sent to Charlie after rearranging the particle orders. With the help of Alice, Bob and Charlie make the corresponding local measurement to obtain the information of the or- thogonal product states prepared. This protocol has many distinct features such as great capacity and high efficiency.
An efficient quantum secret sharing protocol with orthogonal product states
YANG YuGuang; WEN QiaoYan; ZHU FuChen
2007-01-01
An efficient quantum secret sharing protocol with orthogonal product states in the 3(×)3 Hilbert space is presented. The particles in the orthogonal product states form two particle sequences. One sequence is sent to Bob and the other is sent to Charlie after rearranging the particle orders. With the help of Alice, Bob and Charlie make the corresponding local measurement to obtain the information of the orthogonal product states prepared. This protocol has many distinct features such as great capacity and high efficiency.
A Novel Scheme for Image Authentication and Secret Data Sharing
Auqib Hamid Lone
2016-09-01
Full Text Available Privacy protection is of extreme importance especially in security sensitive environments. Neither cryptography nor steganography comes up with ultimate solution for privacy preservation in open systems. However, combination of steganography and cryptography can greatly increase the security of communication and is usually considered a good practice for securing security driven communication environments. In this paper we propose a novel scheme for image authentication and secret data sharing based on three level security model viz: Compression, steganography and cryptography. Compression optimizes the resource usage, steganography conceals the existence of message and cryptography is used to achieve confidentiality and authentication.
Secret Sharing and Secure Computing from Monotone Formulae
Damgård, Ivan Bjerre; Kölker, Jonas; Miltersen, Peter Bro
2012-01-01
We present a construction of log-depth formulae for various threshold functions based on atomic threshold gates of constant size. From this, we build a new family of linear secret sharing schemes that are multiplicative, scale well as the number of players increases and allows to raise a shared...... value to the characteristic of the underlying field without interaction. Some of these schemes are in addition strongly multiplicative. Our formulas can also be used to construct multiparty protocols from protocols for a constant number of parties. In particular we implement black-box multiparty...... computation over non-Abelian groups in a way that is much simpler than previously known and we also show how to get a protocol in this setting that is efficient and actively secure against a constant fraction of corrupted parties, a long standing open problem. Finally, we show a negative result on usage...
A kind of universal quantum secret sharing protocol
Chen, Xiu-Bo; Dou, Zhao; Xu, Gang; He, Xiao-Yu; Yang, Yi-Xian
2017-01-01
Universality is an important feature, but less researched in quantum communication protocols. In this paper, a kind of universal quantum secret sharing protocol is investigated. Firstly, we design a quantum secret sharing protocol based on the Borras-Plastino-Batle (BPB) state. Departing from previous research, our protocol has a salient feature in that participants in our protocol only need projective measurement instead of any unitary operations. It makes our protocol more flexible. Secondly, universality of quantum communication protocols is studied for the first time. More specifically, module division of quantum communication protocols and coupling between different modules are discussed. Our aforementioned protocol is analyzed as an example. On one hand, plenty of quantum states (the BPB-class states and the BPB-like-class states, which are proposed in this paper) could be used as carrier to perform our protocol. On the other hand, our protocol also could be regarded as a quantum private comparison protocol with a little revision. These features are rare for quantum communication protocols, and make our protocol more robust. Thirdly, entanglements of the BPB-class states are calculated in the Appendix.
Jones index, secret sharing and total quantum dimension
Fiedler, Leander; Naaijkens, Pieter; Osborne, Tobias J.
2017-02-01
We study the total quantum dimension in the thermodynamic limit of topologically ordered systems. In particular, using the anyons (or superselection sectors) of such models, we define a secret sharing scheme, storing information invisible to a malicious party, and argue that the total quantum dimension quantifies how well we can perform this task. We then argue that this can be made mathematically rigorous using the index theory of subfactors, originally due to Jones and later extended by Kosaki and Longo. This theory provides us with a ‘relative entropy’ of two von Neumann algebras and a quantum channel, and we argue how these can be used to quantify how much classical information two parties can hide form an adversary. We also review the total quantum dimension in finite systems, in particular how it relates to topological entanglement entropy. It is known that the latter also has an interpretation in terms of secret sharing schemes, although this is shown by completely different methods from ours. Our work provides a different and independent take on this, which at the same time is completely mathematically rigorous. This complementary point of view might be beneficial, for example, when studying the stability of the total quantum dimension when the system is perturbed.
A kind of universal quantum secret sharing protocol.
Chen, Xiu-Bo; Dou, Zhao; Xu, Gang; He, Xiao-Yu; Yang, Yi-Xian
2017-01-12
Universality is an important feature, but less researched in quantum communication protocols. In this paper, a kind of universal quantum secret sharing protocol is investigated. Firstly, we design a quantum secret sharing protocol based on the Borras-Plastino-Batle (BPB) state. Departing from previous research, our protocol has a salient feature in that participants in our protocol only need projective measurement instead of any unitary operations. It makes our protocol more flexible. Secondly, universality of quantum communication protocols is studied for the first time. More specifically, module division of quantum communication protocols and coupling between different modules are discussed. Our aforementioned protocol is analyzed as an example. On one hand, plenty of quantum states (the BPB-class states and the BPB-like-class states, which are proposed in this paper) could be used as carrier to perform our protocol. On the other hand, our protocol also could be regarded as a quantum private comparison protocol with a little revision. These features are rare for quantum communication protocols, and make our protocol more robust. Thirdly, entanglements of the BPB-class states are calculated in the Appendix.
Coding Theorems for Cheating-Detectable Secret Sharing Schemes with Two Shares
Iwamoto, Mitsugu; Yamamoto, Hirosuke
2010-01-01
In this paper, we discuss coding theorems on a $(2, 2)$--threshold scheme in the presence of an opponent who impersonates one of the two shareholders in an asymptotic setup. We consider a situation where $n$ secrets $S^n$ from a memoryless source is blockwisely encoded to two shares and the two shares are decoded to $S^n$ with permitting negligible decoding error. We introduce correlation level of the two shares and characterize the minimum attainable rates of the shares and a uniform random number for realizing a $(2, 2)$--threshold scheme that is secure against the impersonation attack by an opponent. It is shown that, if the correlation level between the two shares equals to an $\\ell \\ge 0$, the minimum attainable rates coincide with $H(S)+\\ell$, where $H(S)$ denotes the entropy of the source, and the maximum attainable exponent of the success probability of the impersonation attack equals to $\\ell$. We also give a simple construction of an encoder and a decoder using an ordinary $(2,2)$--threshold scheme ...
Steganography on multiple MP3 files using spread spectrum and Shamir's secret sharing
Yoeseph, N. M.; Purnomo, F. A.; Riasti, B. K.; Safiie, M. A.; Hidayat, T. N.
2016-11-01
The purpose of steganography is how to hide data into another media. In order to increase security of data, steganography technique is often combined with cryptography. The weakness of this combination technique is the data was centralized. Therefore, a steganography technique is develop by using combination of spread spectrum and secret sharing technique. In steganography with secret sharing, shares of data is created and hidden in several medium. Medium used to concealed shares were MP3 files. Hiding technique used was Spread Spectrum. Secret sharing scheme used was Shamir's Secret Sharing. The result showed that steganography with spread spectrum combined with Shamir's Secret Share using MP3 files as medium produce a technique that could hid data into several cover. To extract and reconstruct the data hidden in stego object, it is needed the amount of stego object which more or equal to its threshold. Furthermore, stego objects were imperceptible and robust.
A New and Efficient Secret Sharing in Graph-Based Prohibited Structures
GUOYuanbo; MAJianfeng
2005-01-01
The secret sharing realizing the prohibited structure, which specifies the corruptible subsets of participants, can be determined directly by exploitation of the system setting and the attributes of all participants. Recently, Sun et al. had proposed a construction of secret sharing for graph-based prohibited structures where a vertex denotes a participant and an edge a pair of participants who cannot recover the secret. But their scheme is inefficient and costly. In this paper, we present a new and efficient secret sharing realizing graph-based prohibited structures and prove that the scheme satisfies both properties of the secret sharing scheme, i.e. the reconstruction property and the perfect property. The main features of our scheme are that it only needs some modular additions and subtractions in both shares assignment phase and secret recovery phase, which is an advantage in terms of computational complexity, and it can achieve higher information rate than existing ones.
Linear VSS and Distributed Commitments Based on Secret Sharing and Pairwise Checks
Fehr, Serge; Maurer, Ueli M.
2002-01-01
We present a general treatment of all non-cryptographic (i.e., information-theoretically secure) linear veriable-secret-sharing (VSS) and distributed-commitment (DC) schemes, based on an underlying secret sharing scheme, pairwise checks between players, complaints, and accusations of the dealer. ...
Authenticated quantum secret sharing with quantum dialogue based on Bell states
Abulkasim, Hussein; Hamad, Safwat; El Bahnasy, Khalid; Rida, Saad Z.
2016-08-01
This work proposes a scheme that combines the advantages of a quantum secret sharing procedure and quantum dialogue. The proposed scheme enables the participants to simultaneously make mutual identity authentications, in a simulated scenario where the boss, Alice, shares a secret with her two agents Bob and Charlie. The secret is protected by checking photons to keep untrustworthy agents and outer attacks from getting useful information. Before the two agents cooperate to recover Alice’s secret, they must authenticate their identity using parts of a pre-shared key. In addition, the whole pre-shared key is reused as part of recovering the secret data to avoid any leaks of information. In comparison with previous schemes, the proposed method can efficiently detect eavesdropping and it is free from information leaks. Furthermore, the proposed scheme proved to be secure against man-in-the-middle attacks, impersonation attacks, entangled-and-measure attacks, participant attacks, modification attacks and Trojan-horse attacks.
Hybrid threshold adaptable quantum secret sharing scheme with reverse Huffman-Fibonacci-tree coding
Lai, Hong; Zhang, Jun; Luo, Ming-Xing; Pan, Lei; Pieprzyk, Josef; Xiao, Fuyuan; Orgun, Mehmet A.
2016-08-01
With prevalent attacks in communication, sharing a secret between communicating parties is an ongoing challenge. Moreover, it is important to integrate quantum solutions with classical secret sharing schemes with low computational cost for the real world use. This paper proposes a novel hybrid threshold adaptable quantum secret sharing scheme, using an m-bonacci orbital angular momentum (OAM) pump, Lagrange interpolation polynomials, and reverse Huffman-Fibonacci-tree coding. To be exact, we employ entangled states prepared by m-bonacci sequences to detect eavesdropping. Meanwhile, we encode m-bonacci sequences in Lagrange interpolation polynomials to generate the shares of a secret with reverse Huffman-Fibonacci-tree coding. The advantages of the proposed scheme is that it can detect eavesdropping without joint quantum operations, and permits secret sharing for an arbitrary but no less than threshold-value number of classical participants with much lower bandwidth. Also, in comparison with existing quantum secret sharing schemes, it still works when there are dynamic changes, such as the unavailability of some quantum channel, the arrival of new participants and the departure of participants. Finally, we provide security analysis of the new hybrid quantum secret sharing scheme and discuss its useful features for modern applications.
An Anti-Cutting Watermarking Algorithm Based on Matrix Multiplication Secret Sharing Scheme
YAO Hui-ming; ZHANG Li-he; SUI Ai-fen
2004-01-01
A digital watermarking algorithm based on the matrix multiplication secret sharing scheme is proposed. It partitions the field of the image into n shares, and also partitions the watermark into n shares correspondingly. After the original image is divided, the digital watermark is embedded into the low frequency DCT domain and only needs part shares in the recovering course. Experimental results show that this algorithm has a good effect of hiding, anti-cutting and anti-compressing.
On the new member's subsecret distribution protocol in dynamic group secret-sharing
LI Cheng; WANG Wei-nong
2005-01-01
Secret-sharing is a common method to protect important data, such as the private key of a public-key system. Dynamic Group Secret-sharing (DGS) is a system where all of the members in a group hold a subsecret of the key information and where the number of members in the group is variable. This kind of secret-sharing is broadly used in many special distribution systems, such as Self-secure Ad-hoc Network. Distributing this subsecret to a new member when he enters the group is the common method that ensures all the members participate in the same secret-sharing. However, no' atisfactory subsecret distribution scheme exists at present. This paper proposes a new protocol that tries to satisfy both security and efficiency.
Two new Controlled not Gate Based Quantum Secret Sharing Protocols without Entanglement Attenuation
Zhu, Zhen-Chao; Hu, Ai-Qun; Fu, An-Min
2016-05-01
In this paper, we propose two new controlled not gate based quantum secret sharing protocols. In these two protocols, each photon only travels once, which guarantees the agents located in long distance can be able to derive the dealer's secret without suffering entanglement attenuation problem. The protocols are secure against trojan horse attack, intercept-resend attack, entangle-measure attack and entanglement-swapping attack. The theoretical efficiency for qubits of these two protocols can approach 100 %, except those used for eavesdropping checking, all entangled states can be used for final secret sharing.
AN EFFICIENT AND SECURE(t,n) THRESHOLD SECRET SHARING SCHEME
Pang Liaojun; Sun Xi; Wang Yumin
2006-01-01
Based on Shamir's threshold secret sharing scheme and the discrete logarithm problem, a new (t,n)threshold secret sharing scheme is proposed in this paper. In this scheme, each participant's secret shadow is selected by the participant himself, and even the secret dealer cannot gain anything about his secret shadow.All the shadows are as short as the shared secret. Each participant can share many secrets with other participants by holding only one shadow. Without extra equations and information designed for verification, each participant is able to check whether another participant provides the true information or not in the recovery phase. Unlike most of the existing schemes, it is unnecessary to maintain a secure channel between each participant and the dealer. Therefore, this scheme is very attractive, especially under the circumstances that there is no secure channel between the dealer and each participant at all. The security of this scheme is based on that of Shamir's threshold scheme and the difficulty in solving the discrete logarithm problem. Analyses show that this scheme is a computationally secure and efficient scheme.
How to Split a Shared Secret into Shared Bits in Constant-Round
Damgård, Ivan Bjerre; Fitzi, Matthias; Nielsen, Jesper Buus
We show that if a set of players hold shares of a value $a\\in Z_p$ for some prime $p$ (where the set of shares is written $[a]_p$), it is possible to compute, in constant round and with unconditional security, sharings of the bits of $a$, i.e.~compute sharings $[a_0]_p, \\ldots, [a_{l-1}]_p...
Applying two channels to vector space secret sharing based multi-signature scheme
XIAO Qing-hua; PING Ling-di; CHEN Xiao-ping; PAN Xue-zeng
2005-01-01
Secret sharing and digital signature is an important research area in information security and has wide applications in such fields as safeguarding and legal use of confidential information, secure multiparty computation and electronic commerce. But up to now, study of signature based on general vector space secret sharing is very weak. Aiming at this drawback, the authors did some research on vector space secret sharing against cheaters, and proposed an efficient but secure vector space secret sharing based multi-signature scheme, which is implemented in two channels. In this scheme, the group signature can be easily produced if an authorized subset of participants pool their secret shadows and it is impossible for them to generate a group signature if an unauthorized subset of participants pool their secret shadows. The validity of the group signature can be verified by means of verification equations. A group signature of authorized subset of participants cannot be impersonated by any other set of participants. Moreover, the suspected forgery can be traced, and the malicious participants can be detected in the scheme. None of several possible attacks can successfully break this scheme.
New Protocols and Lower Bound for Quantum Secret Sharing with Graph States
Javelle, Jérôme; Perdrix, Simon
2011-01-01
We introduce a new family of quantum secret sharing protocols with limited quantum resources which extends the protocols proposed by Markham and Sanders and by Broadbent, Chouha, and Tapp. Parametrized by a graph G and a subset of its vertices A, the protocol consists in: (i) encoding the quantum secret into the corresponding graph state by acting on the qubits in A; (ii) use a classical encoding to ensure the existence of a threshold. These new protocols realize ((k,n)) quantum secret sharing i.e., any set of at least k players among n can reconstruct the quantum secret, whereas any set of less than k players has no information about the secret. In the particular case where the secret is encoded on all the qubits, we explore the values of k for which there exists a graph such that the corresponding protocol realizes a ((k,n)) secret sharing. We show that for any threshold k> n-n^{0.68} there exists a graph allowing a ((k,n)) protocol. On the other hand, we prove that for any kn_0.
Secret Sharing Schemes with a large number of players from Toric Varieties
Hansen, Johan P.
A general theory for constructing linear secret sharing schemes over a finite field $\\Fq$ from toric varieties is introduced. The number of players can be as large as $(q-1)^r-1$ for $r\\geq 1$. We present general methods for obtaining the reconstruction and privacy thresholds as well as conditions...... for multiplication on the associated secret sharing schemes. In particular we apply the method on certain toric surfaces. The main results are ideal linear secret sharing schemes where the number of players can be as large as $(q-1)^2-1$. We determine bounds for the reconstruction and privacy thresholds...... and conditions for strong multiplication using the cohomology and the intersection theory on toric surfaces....
Unconditional security of entanglement-based continuous-variable quantum secret sharing
Kogias, Ioannis; Xiang, Yu; He, Qiongyi; Adesso, Gerardo
2017-01-01
The need for secrecy and security is essential in communication. Secret sharing is a conventional protocol to distribute a secret message to a group of parties, who cannot access it individually but need to cooperate in order to decode it. While several variants of this protocol have been investigated, including realizations using quantum systems, the security of quantum secret sharing schemes still remains unproven almost two decades after their original conception. Here we establish an unconditional security proof for entanglement-based continuous-variable quantum secret sharing schemes, in the limit of asymptotic keys and for an arbitrary number of players. We tackle the problem by resorting to the recently developed one-sided device-independent approach to quantum key distribution. We demonstrate theoretically the feasibility of our scheme, which can be implemented by Gaussian states and homodyne measurements, with no need for ideal single-photon sources or quantum memories. Our results contribute to validating quantum secret sharing as a viable primitive for quantum technologies.
Quantum secret sharing between m-party and n-party with six states
无
2009-01-01
A quantum secret sharing scheme between an m-party group and an n-party group is proposed using three conjugate bases.A sequence of single photons,each of which is prepared in one of the six states,is used directly to encode classical information in the quantum secret sharing process.In this scheme,each of all m members in group 1 chooses randomly his/her own secret key individually and independently,and directly encodes his/her respective secret information on the states of single photons via unitary operations,then the last one sends 1/n of the resulting qubits to each member of group 2.By measuring their respective qubits,all members in group 2 share the secret information shared by all members in group 1.It renders impossible a Trojan horse attack with a multi-photon signal,a fake-signal attack with EPR pairs,an attack with single photons,and an attack with invisible photons.We give the upper bounds on the average success probabilities for dishonest agent eavesdropping encryption using the fake-signal attack with any two-particle entangled states.
Dynamic quantum secret sharing by using d-dimensional GHZ state
Qin, Huawang; Dai, Yuewei
2017-03-01
Through generating the d-dimensional GHZ state in the Z-basis and measuring it in the X-basis, a dynamic quantum secret sharing scheme is proposed. In the proposed scheme, multiple participants can be added or deleted in one update period, and the shared secret does not need to be changed. The participants can be added or deleted by themselves, and the dealer does not need to be online. Compared to the existing schemes, the proposed scheme is more efficient and more practical.
High-dimension multiparty quantum secret sharing scheme with Einstein-Podolsky-Rosen pairs
Chen Pan; Deng Fu-Guo; Long Gui-Lu
2006-01-01
In this paper a high-dimension multiparty quantum secret sharing scheme is proposed by using Einstein-Podolsky-Rosen pairs and local unitary operators. This scheme has the advantage of not only having higher capacity, but also saving storage space. The security analysis is also given.
Probabilistic Visual Secret Sharing Schemes for Gray-scale images and Color images
Wang, Dao-Shun; Li, Xiaobo
2007-01-01
Visual secrete sharing (VSS) is an encryption technique that utilizes human visual system in the recovering of the secret image and it does not require any complex calculation. Pixel expansion has been a major issue of VSS schemes. A number of probabilistic VSS schemes with minimum pixel expansion have been proposed for binary secret images. This paper presents a general probabilistic (k, n)-VSS scheme for gray-scale images and another scheme for color images. With our schemes, the pixel expansion can be set to a user-defined value. When this value is 1, there is no pixel expansion at all. The quality of reconstructed secret images, measured by Average Relative Difference, is equivalent to Relative Difference of existing deterministic schemes. Previous probabilistic VSS schemes for black-and-white images with respect to pixel expansion can be viewed as special cases of the schemes proposed here
Multiparty Quantum Secret Sharing of Classical Message using Cavity Quantum Electrodynamic System
HAN Lian-Fang; LIU Yi-Min; ZHANG Zhan-Jun
2006-01-01
@@ An experimental feasible scheme of multiparty secret sharing of classical messages is proposed, based on a cavity quantum electrodynamic system. The secret messages are imposed on atomic Bell states initially in the sender's possession by local unitary operations. By swapping quantum entanglement of atomic Bell states, the secret messages are split into several parts and each part is distributed to a separate party. In this case, any subset of the entire party group can not read out the secret message but the entirety via mutual cooperations. In this scheme, to discriminate atomic Bell states, additional classical fields are employed besides the same highly-detuned single-mode cavities used to prepare atomic Bell states. This scheme is insensitive to the cavity decay and the thermal field, and usual joint Bell-state measurements are unnecessary.
Rate Regions of Secret Key Sharing in a New Source Model
Salimi, Somayeh; Aref, Mohammad Reza
2010-01-01
A source model for secret key generation between terminals is considered. Two users, namely users 1 and 2, at one side communicate with another user, namely user 3, at the other side via a public channel where three users can observe i.i.d. outputs of correlated sources. Each of users 1 and 2 intends to share a secret key with user 3 where user 1 acts as a wiretapper for user 2 and vice versa. In this model, two situations are considered: communication from users 1 and 2 to user 3 (the forward key strategy) and from user 3 to users 1 and 2 (the backward key strategy). In both situations, the goal is sharing a secret key between user 1 and user 3 while leaking no effective information about that key to user 2, and simultaneously, sharing another secret key between user 2 and user 3 while leaking no effective information about the latter key to user 1. This model is motivated by wireless communications when considering user 3 as a base station and users 1 and 2 as network users. In this paper, for both the forw...
Graph State-Based Quantum Secret Sharing with the Chinese Remainder Theorem
Guo, Ying; Luo, Peng; Wang, Yijun
2016-07-01
Quantum secret sharing (QSS) is a significant quantum cryptography technology in the literature. Dividing an initial secret into several sub-secrets which are then transferred to other legal participants so that it can be securely recovered in a collaboration fashion. In this paper, we develop a quantum route selection based on the encoded quantum graph state, thus enabling the practical QSS scheme in the small-scale complex quantum network. Legal participants are conveniently designated with the quantum route selection using the entanglement of the encoded graph states. Each participant holds a vertex of the graph state so that legal participants are selected through performing operations on specific vertices. The Chinese remainder theorem (CRT) strengthens the security of the recovering process of the initial secret among the legal participants. The security is ensured by the entanglement of the encoded graph states that are cooperatively prepared and shared by legal users beforehand with the sub-secrets embedded in the CRT over finite fields.
Graph State-Based Quantum Secret Sharing with the Chinese Remainder Theorem
Guo, Ying; Luo, Peng; Wang, Yijun
2016-11-01
Quantum secret sharing (QSS) is a significant quantum cryptography technology in the literature. Dividing an initial secret into several sub-secrets which are then transferred to other legal participants so that it can be securely recovered in a collaboration fashion. In this paper, we develop a quantum route selection based on the encoded quantum graph state, thus enabling the practical QSS scheme in the small-scale complex quantum network. Legal participants are conveniently designated with the quantum route selection using the entanglement of the encoded graph states. Each participant holds a vertex of the graph state so that legal participants are selected through performing operations on specific vertices. The Chinese remainder theorem (CRT) strengthens the security of the recovering process of the initial secret among the legal participants. The security is ensured by the entanglement of the encoded graph states that are cooperatively prepared and shared by legal users beforehand with the sub-secrets embedded in the CRT over finite fields.
Encryption On Grayscale Image For Digital Image Confidentiality Using Shamir Secret Sharing Scheme
Rodiah; Anggraini, Dyah; Fitrianingsih; Kazhimi, Farizan
2016-04-01
The use of high-frequency internet in the process of exchanging information and digital transaction is often accompanied by transmitting digital image in the form of raster images. Secret sharing schemes are multiparty protocols that related to the key establishment which provides protection against any threats of losing cryptography key. The greater the key duplication, the higher the risk of losing the key and vice versa. In this study, Secret Sharing Method was used by employing Shamir Threshold Scheme Algorithm on grayscale digital image with the size of 256×256 pixel obtaining 128×128 pixels of shared image with threshold values (4, 8). The result number of shared images were 8 parts and the recovery process can be carried out by at least using 4 shares of the 8 parts. The result of encryption on grayscale image is capable of producing vague shared image (i.e., no perceptible information), therefore a message in the form of digital image can be kept confidential and secure.
Cryptanalysis and improvement of a quantum secret sharing scheme based on x-type entangled states
Zhu Zhen-Chao; Zhang Yu-Qing; Fu An-Min
2012-01-01
In the paper [2010 Chin.Phys.B 19 050306],Yang et al.put forward a novel three-party quantum secret sharing protocol of secure direct communication based on x-type entangled states,they claimed that the scheme is secure.However,in this paper,we study the security of the protocol and find that it is insecure.Applying intercept and resend attack,the agent Bob can obtain Alice's secret without the help from the other agent Charlie.In the end,we give our effective modification for its improvement.
Fujiwara, M; Waseda, A; Nojima, R; Moriai, S; Ogata, W; Sasaki, M
2016-07-01
Distributed storage plays an essential role in realizing robust and secure data storage in a network over long periods of time. A distributed storage system consists of a data owner machine, multiple storage servers and channels to link them. In such a system, secret sharing scheme is widely adopted, in which secret data are split into multiple pieces and stored in each server. To reconstruct them, the data owner should gather plural pieces. Shamir's (k, n)-threshold scheme, in which the data are split into n pieces (shares) for storage and at least k pieces of them must be gathered for reconstruction, furnishes information theoretic security, that is, even if attackers could collect shares of less than the threshold k, they cannot get any information about the data, even with unlimited computing power. Behind this scenario, however, assumed is that data transmission and authentication must be perfectly secure, which is not trivial in practice. Here we propose a totally information theoretically secure distributed storage system based on a user-friendly single-password-authenticated secret sharing scheme and secure transmission using quantum key distribution, and demonstrate it in the Tokyo metropolitan area (≤90 km).
Fujiwara, M.; Waseda, A.; Nojima, R.; Moriai, S.; Ogata, W.; Sasaki, M.
2016-07-01
Distributed storage plays an essential role in realizing robust and secure data storage in a network over long periods of time. A distributed storage system consists of a data owner machine, multiple storage servers and channels to link them. In such a system, secret sharing scheme is widely adopted, in which secret data are split into multiple pieces and stored in each server. To reconstruct them, the data owner should gather plural pieces. Shamir’s (k, n)-threshold scheme, in which the data are split into n pieces (shares) for storage and at least k pieces of them must be gathered for reconstruction, furnishes information theoretic security, that is, even if attackers could collect shares of less than the threshold k, they cannot get any information about the data, even with unlimited computing power. Behind this scenario, however, assumed is that data transmission and authentication must be perfectly secure, which is not trivial in practice. Here we propose a totally information theoretically secure distributed storage system based on a user-friendly single-password-authenticated secret sharing scheme and secure transmission using quantum key distribution, and demonstrate it in the Tokyo metropolitan area (≤90 km).
Fujiwara, M.; Waseda, A.; Nojima, R.; Moriai, S.; Ogata, W.; Sasaki, M.
2016-01-01
Distributed storage plays an essential role in realizing robust and secure data storage in a network over long periods of time. A distributed storage system consists of a data owner machine, multiple storage servers and channels to link them. In such a system, secret sharing scheme is widely adopted, in which secret data are split into multiple pieces and stored in each server. To reconstruct them, the data owner should gather plural pieces. Shamir’s (k, n)-threshold scheme, in which the data are split into n pieces (shares) for storage and at least k pieces of them must be gathered for reconstruction, furnishes information theoretic security, that is, even if attackers could collect shares of less than the threshold k, they cannot get any information about the data, even with unlimited computing power. Behind this scenario, however, assumed is that data transmission and authentication must be perfectly secure, which is not trivial in practice. Here we propose a totally information theoretically secure distributed storage system based on a user-friendly single-password-authenticated secret sharing scheme and secure transmission using quantum key distribution, and demonstrate it in the Tokyo metropolitan area (≤90 km). PMID:27363566
Optimistic fair exchange E-commerce protocol based on secret sharing
Ma Changshe; Lei Feiyu; Chen Kefei
2006-01-01
A key problem of electronic commerce (for short e-commerce) is fair exchange which guarantees that at the end of the transaction, either both parties involved in the transaction receive each other's items or none do. A non-interactive optimistic fair exchange e-commerce protocol model based on the publicly verifiable secret sharing is presented. The main idea of our exchange protocol is to interchange verifiable and recoverable keys of the symmetric encryption for participants' items. So it is especially suitable for exchange of large-size items. Furthermore, our protocol is efficient and simple as it does not need interactive proof system which has been adopted by a large quantity of previously proposed fair exchange protocols. Based on a modified (2,2) secret sharing scheme, a concrete non-interactive fair exchange e-commerce protocol is designed.
SECRET SHARING SCHEMES WITH STRONG MULTIPLICATION AND A LARGE NUMBER OF PLAYERS FROM TORIC VARIETIES
Hansen, Johan Peder
2016-01-01
This article consider Massey's construction for constructing linear secret sharing schemes from toric varieties over a finite field $\\Fq$ with $q$ elements. The number of players can be as large as $(q-1)^r-1$ for $r\\geq 1$. The schemes have strong multiplication, such schemes can be utilized in ...... schemes where the number of players can be as large as $(q-1)^2-1$, we determine bounds for the reconstruction and privacy thresholds and conditions for strong multiplication using the cohomology and the intersection theory on toric surfaces.......This article consider Massey's construction for constructing linear secret sharing schemes from toric varieties over a finite field $\\Fq$ with $q$ elements. The number of players can be as large as $(q-1)^r-1$ for $r\\geq 1$. The schemes have strong multiplication, such schemes can be utilized...
High-capacity three-party quantum secret sharing with superdense coding
Gu Bin; Li Chuan-Qi; Xu Fei; Chen Yu-Lin
2009-01-01
This paper presents a scheme for high-capacity three-party quantum secret sharing with quantum superdense coding, following some ideas in the work by Liu et al (2002 Phys. Rev. A 65 022304) and the quantum secret sharing scheme by Deng et al (2008 Phys. Left. A 372 1957). Instead of using two sets of nonorthogonal states, the boss Alice needs only to prepare a sequence of Einstein-Podolsky-Rosen pairs in d-dimension. The two agents Bob and Charlie encode their information with dense coding unitary operations, and security is checked by inserting decoy photons. The scheme has a high capacity and intrinsic efficiency as each pair can carry 21bd bits of information, and almost all the pairs can be used for carrying useful information.
Arya Widyadhana
2012-09-01
Full Text Available Teknik yang banyak digunakan untuk menyebarkan suatu citra rahasia kepada n orang adalah dengan cara membagi citra rahasia ke dalam beberapa bagian yang kemudian diproses menggunakan skema (k, n-Shamir Secret Sharing yang dikemukakan oleh Adi Shamir (1979. Bagian-bagian dari citra rahasia yang sudah diproses tersebut disisipkan ke dalam n citra kamuflase dan menghasilkan n citra stego. Penyisipan dilakukan sedemikian rupa sehingga kualitas visual citra stego semirip mungkin dengan citra kamuflase. Cara untuk memproteksi citra stego dari orang yang tidak berhak adalah dengan cara menyisipkan suatu bit otentikasi yang berfungsi sebagai suatu digital signature dari citra stego. Citra rahasia dapat dirangkai kembali jika terdapat minimal k citra stego asli. Teknik ini dinamakan Secret Image Sharing.
YAN Feng-Li; GAO Ting; LI You-Cheng
2008-01-01
@@ We propose a scheme of quantum secret sharing between Alice's group and Bob's group with single photons and unitary transformations. In the protocol, one member in Alice's group prepares a sequence of single photons in one of four different states, while other members directly encode their information on the sequence of single photons via unitary operations; after that, the last member sends the sequence of single photons to Bob's group.Then Bob's, except for the last one, do work similarly. Finally the last member in Bob's group measures the qubits. If the security of the quantum channel is guaranteed by some tests, then the qubit states sent by the last member of Alice's group can be used as key bits for secret sharing. It is shown that this scheme is safe.
Ramp Secret Sharing Approach to Authentication and Data Repairing For Document Image
Larry Liston
2014-04-01
Full Text Available Digital images are widely used to protect confidential and important information. But the problem is to provide the authentication and integrity to these digital images is a very challenging task. Therefore a new efficient authentication method is proposed for document images with verification and data self-repair capability using the Portable Network Graphics (PNG image. Here, an authentication signal is generated for each block of a document image which, combine with the binarized block data, is transformed into several shares using the Ramp secret sharing scheme. These several binarized block data shares are then embedded into an alpha channel plane. During the embedding process, the generated share values are mapped into a range of 238-255 to yield a transparent stego-image with a disguise effect. Alpha channel is combining with the original image and converted into PNG image format. While the process of image authentication, the image block is marked as tampered, if the authentication signal generated from the current block content does not match with share that extracted from the alpha channel plane. Then using reverse Ramp scheme, two shares from unmarked blocks are collected and then data repairing is applied. Some security measures are also proposed for protecting the security of the shares hidden in the alpha channel.
一种基于密钥矩阵的动态秘密分享方案%A Dynamic Secret Sharing Scheme Based on Key Matrix
颜浩; 陈克非
2003-01-01
In this paper we introduce a dynamic secret sharing scheme. This scheme not only can be used unrestrictedtimes to share and resume different secret without regenerating the information in the users hands,satisfy the (k,n)threshold demand ,but also can realize the asymmetric user right secret sharing and dynamically add and delete the rel-evant users.
Large-Capacity Three-Party Quantum Digital Secret Sharing Using Three Particular Matrices Coding
Lai, Hong; Luo, Ming-Xing; Pieprzyk, Josef; Tao, Li; Liu, Zhi-Ming; Orgun, Mehmet A.
2016-11-01
In this paper, we develop a large-capacity quantum digital secret sharing (QDSS) scheme, combined the Fibonacci- and Lucas-valued orbital angular momentum (OAM) entanglement with the recursive Fibonacci and Lucas matrices. To be exact, Alice prepares pairs of photons in the Fibonacci- and Lucas-valued OAM entangled states, and then allocates them to two participants, say, Bob and Charlie, to establish the secret key. Moreover, the available Fibonacci and Lucas values from the matching entangled states are used as the seed for generating the Fibonacci and Lucas matrices. This is achieved because the entries of the Fibonacci and Lucas matrices are recursive. The secret key can only be obtained jointly by Bob and Charlie, who can further recover the secret. Its security is based on the facts that nonorthogonal states are indistinguishable, and Bob or Charlie detects a Fibonacci number, there is still a twofold uncertainty for Charlie' (Bob') detected value. Supported by the Fundamental Research Funds for the Central Universities under Grant No. XDJK2016C043 and the Doctoral Program of Higher Education under Grant No. SWU115091, the National Natural Science Foundation of China under Grant No. 61303039, the Fundamental Research Funds for the Central Universities under Grant No. XDJK2015C153 and the Doctoral Program of Higher Education under Grant No. SWU114112, and the Financial Support the 1000-Plan of Chongqing by Southwest University under Grant No. SWU116007
On the Security of Black-Box Implementation of Visual Secret Sharing Schemes
Adrian Atanasiu
2012-03-01
Full Text Available Cryptographic software and devices give users the ability to take advantage of the benefits of cryptography more easily. However, this implies that the users must totally trust the manufacturer and the authenticity of the device or software they use. Young and Yung were the first to question the correctness of the manufacturer and considered the advantage that a malicious implementation could offer to a specific attacker. In this paper, we consider a modified version of two visual secret sharing schemes and the advantage that they provide to the attacker in order to reconstruct the secret by himself, while the other participants must fulfill the honest scheme reconstruction conditions. We also analyze the security of the proposed mechanisms and the conditions in which they can be applicable.
Algebra for applications cryptography, secret sharing, error-correcting, fingerprinting, compression
Slinko, Arkadii
2015-01-01
This book examines the relationship between mathematics and data in the modern world. Indeed, modern societies are awash with data which must be manipulated in many different ways: encrypted, compressed, shared between users in a prescribed manner, protected from an unauthorised access and transmitted over unreliable channels. All of these operations can be understood only by a person with knowledge of basics in algebra and number theory. This book provides the necessary background in arithmetic, polynomials, groups, fields and elliptic curves that is sufficient to understand such real-life applications as cryptography, secret sharing, error-correcting, fingerprinting and compression of information. It is the first to cover many recent developments in these topics. Based on a lecture course given to third-year undergraduates, it is self-contained with numerous worked examples and exercises provided to test understanding. It can additionally be used for self-study.
Thiyagarajan, P.; Thandra, Prasanth Kumar; Rajan, J.; Satyamurthy, S.A.V. [Indira Gandhi Centre for Atomic Research (IGCAR), Kalpakkam (India). Computer Div.; Aghila, G. [National Institute of Technology, Karaikal (India). Dept. of Computer Science and Engineering
2015-05-15
In recent years, due to the sophistication offered by the Internet, strategic organizations like nuclear power plants are linked to the outside world communication through the Internet. The entry of outside world communication into strategic organization (nuclear power plant) increases the hacker's attempts to crack its security and to trace any information which is being sent among the top level officials. Information security system in nuclear power plant is very crucial as even small loophole in the security system will lead to a major disaster. Recent cyber attacks in nuclear power plant provoked information security professionals to look deeply into the information security aspects of strategic organizations (nuclear power plant). In these lines, Shamir secret sharing scheme with dynamic access structure (SSSDAS) is proposed in the paper which provides enhanced security by providing dynamic access structure for each node in different hierarchies. The SSSDAS algorithm can be applied to any strategic organizations with hierarchical structures. In this paper the possible scenarios where SSSDAS algorithm can be applied to nuclear power plant is explained as a case study. The proposed SSSDAS scheme identifies the wrong shares, if any, used for reconstruction of the secret. The SSSDAS scheme also address the three major security parameters namely confidentiality, authentication and integrity.
A Secure and Efficient Scalable Secret Image Sharing Scheme with Flexible Shadow Sizes.
Xie, Dong; Li, Lixiang; Peng, Haipeng; Yang, Yixian
2017-01-01
In a general (k, n) scalable secret image sharing (SSIS) scheme, the secret image is shared by n participants and any k or more than k participants have the ability to reconstruct it. The scalability means that the amount of information in the reconstructed image scales in proportion to the number of the participants. In most existing SSIS schemes, the size of each image shadow is relatively large and the dealer does not has a flexible control strategy to adjust it to meet the demand of differen applications. Besides, almost all existing SSIS schemes are not applicable under noise circumstances. To address these deficiencies, in this paper we present a novel SSIS scheme based on a brand-new technique, called compressed sensing, which has been widely used in many fields such as image processing, wireless communication and medical imaging. Our scheme has the property of flexibility, which means that the dealer can achieve a compromise between the size of each shadow and the quality of the reconstructed image. In addition, our scheme has many other advantages, including smooth scalability, noise-resilient capability, and high security. The experimental results and the comparison with similar works demonstrate the feasibility and superiority of our scheme.
A Secure and Efficient Scalable Secret Image Sharing Scheme with Flexible Shadow Sizes
Xie, Dong; Li, Lixiang; Peng, Haipeng; Yang, Yixian
2017-01-01
In a general (k, n) scalable secret image sharing (SSIS) scheme, the secret image is shared by n participants and any k or more than k participants have the ability to reconstruct it. The scalability means that the amount of information in the reconstructed image scales in proportion to the number of the participants. In most existing SSIS schemes, the size of each image shadow is relatively large and the dealer does not has a flexible control strategy to adjust it to meet the demand of differen applications. Besides, almost all existing SSIS schemes are not applicable under noise circumstances. To address these deficiencies, in this paper we present a novel SSIS scheme based on a brand-new technique, called compressed sensing, which has been widely used in many fields such as image processing, wireless communication and medical imaging. Our scheme has the property of flexibility, which means that the dealer can achieve a compromise between the size of each shadow and the quality of the reconstructed image. In addition, our scheme has many other advantages, including smooth scalability, noise-resilient capability, and high security. The experimental results and the comparison with similar works demonstrate the feasibility and superiority of our scheme. PMID:28072851
Improvement on the Multihop Shareholder Discovery for ThresholdSecret Sharing in MANETs
Seleviawati Tarmizi; Prakash Veeraraghavan; Somnath Ghosh
2011-01-01
The collaboration of at least a threshold number of secret shareholders in a threshold secret sharing scheme is a strict requirement to ensure its intended functionality.Due to its promising characteristics,such a scheme has been proposed to solve a range of security problems in mobile ad hoc networks.However,discovering a sufficient number of secret shareholders in such dynamic and unpredictable networks is not easy.In this paper,we propose a more efficient shareholder discovery mechanism compared to our previous work.The discovery process is performed in a multihop fashion to adapt to the mobile ad hoc network environment.We introduce batch extension that gradually extends the shareholders' collaboration boundary by more than one hop at a time around the service requestor,to find at least the threshold number of the unknown shareholders.Through the batch extension,reply aggregation is applicable,hence reducing the redundancy use of reply routes,decreasing the required packet transmission,and lessening the service delay,compared to the previously proposed mechanism.Our simulation results show that,with the appropriate batch size,the latest mechanism is more efficient with an insignificant increase of control overhead.
Efficient Multiparty Quantum Secret Sharing with Greenberger-Horne-Zeilinger States
DENG Fu-Guo; ZHOU Ping; LI Xi-Han; LI Chun-Yan; ZHOU Hong-Yu
2006-01-01
@@ An efficient multiparty quantum secret sharing scheme is proposed with Greenberger-Horne-Zeilinger (GHZ)states following some ideas in quantum dense coding. The agents take the single-photon measurements on the photons received for eavesdropping check and exploit the four local unitary operations I, σz, σx and iσy tocode their message. This scheme has the advantage of high capacity as each GHZ state can carry two bits of information. The parties do not need to announce the measuring bases for almost all the photons, which will reduce the classical information exchanged largely. The intrinsic efficiency for qubits and the total efficiency both approach the maximal values.
DISTRIBUTED CERTIFICATE AUTHORITY IN CLUSTER-BASED MANET USING MULTI SECRET SHARING SCHEME
Mohammed Azza
2015-11-01
Full Text Available Providing secure communications in mobile ad hoc networks (MANET is an important and difficult problem, due to a lack of a key management infrastructure. The authentication is an important security service in (MANETs. To provide a node authentication service we use a fully distributed certificate authorities (FDCA based on the threshold cryptography. In this paper we propose an efficient and verifiable multi secret sharing scheme in cluster-based MANET with a low computation system. Our scheme is based on the overdetermined linear system equation in Galois fields GF(2r. We have analyzed our scheme based on security and performance criteria, and compared with existing approaches. The efficiency of our proposed schemes was verified and evaluated by simulation. Simulation results show that this approach is scalable.
Wang, Jingtao; Li, Lixiang; Peng, Haipeng; Yang, Yixian
2017-02-01
In this study, we propose the concept of judgment space to investigate the quantum-secret-sharing scheme based on local distinguishability (called LOCC-QSS). Because of the proposing of this conception, the property of orthogonal mutiqudit entangled states under restricted local operation and classical communication (LOCC) can be described more clearly. According to these properties, we reveal that, in the previous (k ,n )-threshold LOCC-QSS scheme, there are two required conditions for the selected quantum states to resist the unambiguous attack: (i) their k -level judgment spaces are orthogonal, and (ii) their (k -1 )-level judgment spaces are equal. Practically, if k security, i.e., even if the (k -1 )-level judgment spaces of the selected quantum states are not equal, these states can still be used for defeating the unambiguous attack. With this encoding method, we propose a more secure (k ,n )-threshold LOCC-QSS scheme, and give two specific examples for illustration.
Improving the security of multiparty quantum secret sharing against Trojan horse attack
Deng, F G; Deng, Fu-Guo; Zhou, Hong-Yu
2005-01-01
Security of the multiparty quantum secret sharing (MQSS) protocol recently proposed by Zhang et al. [Phys. Rev. A \\textbf{71}, 044301 (2005)] is analyzed in the case that the agent who prepares the quantum signal, say Bob wants to eavesdrop the information about the unitary operations done by the other agent, Charlie by using a Trojan horse attack. Bob can replace the single-photon signal with a multi-photon one and Charlie cannot find this cheating as she does not measure the photons before they runs back from the boss Alice, which reveals that this MQSS protocol is not secure. Finally, we present a possible improvement of the MQSS protocol security with two single-photon measurements and four unitary operations.
Constructing UC Secure and Constant-Round Group Key Exchange Protocols via Secret Sharing
Sangjae Moon
2008-07-01
Full Text Available Group key exchange (GKE is one of the basic building blocks in securing group communication. A number of solutions to GKE problem have been proposed, but most of them are not scalable and require a number of rounds linear with the number of group members. We present a method of constructing constant-round and identity-based protocol via secret sharing for GKE within universally composability (UC framework. The resultant protocol focuses on round efficiency and three rounds of communication are required. The protocol allows the batch verification of messages signed by all other group participants. Moreover, compared with other identity-based protocols, the key generation center (KGC in our protocol is not always online.
Constructing UC Secure and Constant-Round Group Key Exchange Protocols via Secret Sharing
Moon Sangjae
2008-01-01
Full Text Available Abstract Group key exchange (GKE is one of the basic building blocks in securing group communication. A number of solutions to GKE problem have been proposed, but most of them are not scalable and require a number of rounds linear with the number of group members. We present a method of constructing constant-round and identity-based protocol via secret sharing for GKE within universally composability (UC framework. The resultant protocol focuses on round efficiency and three rounds of communication are required. The protocol allows the batch verification of messages signed by all other group participants. Moreover, compared with other identity-based protocols, the key generation center (KGC in our protocol is not always online.
A novel lost packets recovery scheme based on visual secret sharing
Lu, Kun; Shan, Hong; Li, Zhi; Niu, Zhao
2017-08-01
In this paper, a novel lost packets recovery scheme which encrypts the effective parts of an original packet into two shadow packets based on (2, 2)-threshold XOR-based visual Secret Sharing (VSS) is proposed. The two shadow packets used as watermarks would be embedded into two normal data packets with digital watermarking embedding technology and then sent from one sensor node to another. Each shadow packet would reveal no information of the original packet, which can improve the security of original packet delivery greatly. The two shadow packets which can be extracted from the received two normal data packets delivered from a sensor node can recover the original packet lossless based on XOR-based VSS. The Performance analysis present that the proposed scheme provides essential services as long as possible in the presence of selective forwarding attack. The proposed scheme would not increase the amount of additional traffic, namely, lower energy consumption, which is suitable for Wireless Sensor Network (WSN).
A secure data outsourcing scheme based on Asmuth-Bloom secret sharing
Idris Muhammad, Yusuf; Kaiiali, Mustafa; Habbal, Adib; Wazan, A. S.; Sani Ilyasu, Auwal
2016-11-01
Data outsourcing is an emerging paradigm for data management in which a database is provided as a service by third-party service providers. One of the major benefits of offering database as a service is to provide organisations, which are unable to purchase expensive hardware and software to host their databases, with efficient data storage accessible online at a cheap rate. Despite that, several issues of data confidentiality, integrity, availability and efficient indexing of users' queries at the server side have to be addressed in the data outsourcing paradigm. Service providers have to guarantee that their clients' data are secured against internal (insider) and external attacks. This paper briefly analyses the existing indexing schemes in data outsourcing and highlights their advantages and disadvantages. Then, this paper proposes a secure data outsourcing scheme based on Asmuth-Bloom secret sharing which tries to address the issues in data outsourcing such as data confidentiality, availability and order preservation for efficient indexing.
Fault-Tolerate Three-Party Quantum Secret Sharing over a Collective-Noise Channel
LI Chun-Yan; LI Yan-Song
2011-01-01
We present a fault-tolerate three-party quantum secret sharing (QSS) scheme over a collective-noise channel.Decoherence-free subspaces are used to tolerate two noise modes, a collective-dephasing channel and a collective-rotating channel, respectively. In this scheme, the boss uses two physical qubits to construct a logical qubit which acts as a quantum channel to transmit one bit information to her two agents. The agents can get the information of the private key established by the boss only if they collaborate. The boss Alice encodes information with two unitary operations. Only single-photon measurements are required to rebuilt Alice's information and detect the security by the agents Bob and Charlie, not Bell-state measurements. Moreover, Almost all of the photons are used to distribute information, and its success efficiency approaches 100％ in theory.%@@ We present a fault-tolerate three-party quantum secret sharing (QSS) scheme over a collective-noise channel.Decoherence-free subspaces are used to tolerate two noise modes, a collective-dephasing channel and a collective-rotating channel, respectively.In this scheme, the boss uses two physical qubits to construct a logical qubit which acts as a quantum channel to transmit one bit information to her two agents.The agents can get the information of the private key established by the boss only if they collaborate.The boss Alice encodes information with two unitary operations.Only single-photon measurements are required to rebuilt Alice's information and detect the security by the agents Bob and Charlie, not Bell-state measurements.Moreover, Almost all of the photons are used to distribute information, and its success efficiency approaches 100% in theory.
Shared secrets: Web 2.0 and research in Social Sciences
Sandra MARTORELL
2013-12-01
Full Text Available Web 2.0 represents a revolution in terms of the possibilities it offers for facilitating communication and collaboration between users – something that has become increasingly common in the world of research. A mere few years ago, the information produced by scientists and scholars remained in the hands of a very limited circle of institutions and publishers, as if it were a guarded secret. Today that secret is being shouted from the rooftops and shared with the rest of the scientific community in order to make it more accessible and to allow new advances. A clear example of this can be found in the social sciences, where there is a constant increase in the production of articles and materials that in turn serve for the pursuit of further research, thereby promoting the continuous development of scientific knowledge. This new situation is being fostered by the proliferation of tools and applications that make it possible, but also by a change in mentality towards a philosophy of exchange and open access. In this article, we will examine this phenomenon using a methodological system based on the analysis of platforms for the exchange of scientific knowledge, and especially social networks (both general and specialising in the social sciences, in order to demonstrate their potential in a society that is becoming increasingly aware of the need to overcome physical or institutional boundaries and move forward together.
Cheng, X.; Degryse, H.A.
2010-01-01
We provide the first evidence on how the introduction of information sharing via a public credit registry affects banks’ lending decisions. We employ a unique dataset containing detailed information on credit card applications and decisions from one of the leading banks in China. While we do not
Cheng, X.; Degryse, H.A.
2010-01-01
We provide the first evidence on how the introduction of information sharing via a public credit registry affects banks’ lending decisions. We employ a unique dataset containing detailed information on credit card applications and decisions from one of the leading banks in China. While we do not fin
B3A: Prompting Cooperation Among Rational Participants in P2P Bulk File Sharing Environments
无
2006-01-01
Peer-to-peer (P2P) file sharing systems assume that their users download files in proportion to their sharing. Unfortunately, users are unlikely to do so without an incentive mechanism. Previous solutions to the problem required some types of centralized control, which strays from the spirit of P2P to provide long-term incentives. This paper presents the balance-based bandwidth allocation, B3A, an incentive framework to inspire participants to share files. In the B3A framework, each peer keeps the differences between the amount of data it has received from each peer and the amount it has sent to that one. When receiving simultaneous requests from various peers, the peer prefers to allocate its limited upload bandwidth to those peers with larger differences. Therefore, the downloading bandwidth perceived by a peer is positively related to its contributions to others, consequently stimulating it to share more files. The B3A framework is fully decentralized, scalable, and secure.
Block Access Token Renewal Scheme Based on Secret Sharing in Apache Hadoop
Su-Hyun Kim
2014-07-01
Full Text Available In a cloud computing environment, user data is encrypted and stored using a large number of distributed servers. Global Internet service companies such as Google and Yahoo have recognized the importance of Internet service platforms and conducted their own research and development to utilize large cluster-based cloud computing platform technologies based on low-cost commercial off-the-shelf nodes. Accordingly, as various data services are now allowed over a distributed computing environment, distributed management of big data has become a major issue. On the other hand, security vulnerability and privacy infringement due to malicious attackers or internal users can occur by means of various usage types of big data. In particular, various security vulnerabilities can occur in the block access token, which is used for the permission control of data blocks in Hadoop. To solve this problem, we have proposed a weight-applied XOR-based efficient distribution storage and recovery scheme in this paper. In particular, various security vulnerabilities can occur in the block access token, which is used for the permission control of data blocks in Hadoop. In this paper, a secret sharing-based block access token management scheme is proposed to overcome such security vulnerabilities.
A Dynamic Key Management Scheme Based on Secret Sharing for Hierarchical Wireless Sensor Networks
Enjian Bai
2013-01-01
Full Text Available Since wireless sensor networks (WSN for short are often deployed in hostile environments in many applications, security becomes one of the critical issues in WSN. Moreover, due to the limitation of the sensor nodes, traditional key management schemes are not suitable for it. Thereby,a feasible and efficient key management scheme is an important guarantee for WSN to communicate securely. For the moment, many protocols have been proposed and each has its own advantages. However, these protocols cannot provide sufficient security in many cases, such as node capture attack, which makes WSN more vulnerable than traditional wireless networks. Key protection and revocation issues must be considered with special attention in WSN. To address these two issues, we propose a dynamically clustering key management scheme based on secret sharing for WSN. The scheme combined the hierarchical structure of wireless sensor networks with dynamic key management scheme. The analysis results show that the scheme has strong security and resistance of captured attack, as well as low communicational overhead, and it well meets the requirement of scalability.
Novel and effective secret sharing scheme%新型有效的秘密共享方案
石润华; 黄刘生; 杨威; 仲红
2012-01-01
提出了一种新的秘密共享方案.该方案分两层实现:上层,基于Stern-Brocot树把一个大的秘密拆分为t个小整数(子秘密)；底层,借鉴一维元胞自动机模型中的进化方法,把上层的t个子秘密作为初始状态,动态生成各参与者的共享.特别地,该方案能够动态扩展参与者,动态调整门限值,动态更新秘密和共享.另外,还具有计算简单,各参与者共享份额短的优点.分析结果表明,该方案安全、有效.%A novel secret sharing scheme was proposed. This scheme consisted of two layer protocols: in the first layer, a larger secret was split into / smaller integers (sub-secrets) based on the Stern-Brocot tree; in the lower layer, (sub-secrets obtained from the first layer were regarded as t initial states in one-dimensional cellular automaton model, and then from the t initial states it could dynamic create all participants' shares according to the simple fixed rule. This scheme could dynamic add new member, adjust the threshold value and renew the secret and the shares. Besides, there were still other advantages that the costs of the computation were very low and the size of the shares was very small. The results of analysis show that it was secure and very efficient.
Attasena, Varunya; Harbi, Nouria; Darmont, Jérôme
2015-01-01
International audience; Cloud computing helps reduce costs, increase business agility and deploy solutions with a high return on investment for many types of applications, including data warehouses and on-line analytical processing. However, storing and transferring sensitive data into the cloud raises legitimate security concerns. In this paper, we propose a new multi-secret sharing approach for deploying data warehouses in the cloud and allowing on-line analysis processing, while enforcing ...
Attasena, Varunya; Harbi, Nouria; Darmont, Jérôme
2017-01-01
Cloud computing helps reduce costs, increase business agility and deploy solutions with a high return on investment for many types of applications, including data warehouses and on-line analytical processing. However, storing and transferring sensitive data into the cloud raises legitimate security concerns. In this paper, we propose a new multi-secret sharing approach for deploying data warehouses in the cloud and allowing on-line analysis processing, while enforcing data privacy, integrity ...
Proactive secret sharing scheme without trusted party%一种无可信中心动态秘密共享方案
何二庆; 侯整风; 朱晓玲
2013-01-01
Some existing secret sharing schemes have not researched the proactive refreshment of new members' secret shares, which greatly reduced the security of the secret sharing system. Against this defect researched, this paper put forward a new proactive secret sharing scheme without trusted part, without exposing the original secret, all members can interact collab-oratively, refresh their secret shares proactively, and add new members. What' s more, new members could also proactively refresh their secret shares with other members at next time period.%现有的无可信中心动态秘密共享方案,尚未对新增成员秘密份额的动态更新问题作相关研究,在很大程度上降低了秘密共享系统的安全性.针对这一缺陷进行研究,提出了一种新的无可信中心动态秘密共享方案,在不暴露原秘密的情况下,成员可以协同交互,动态地更新各自的秘密份额,增加新成员,且新增成员也可以与其他成员协同参加下一轮秘密份额的动态更新.
Li, Xianye; Meng, Xiangfeng; Wang, Yurong; Yang, Xiulun; Yin, Yongkai; Peng, Xiang; He, Wenqi; Dong, Guoyan; Chen, Hongyi
2017-09-01
A multiple-image encryption method is proposed that is based on row scanning compressive ghost imaging, (t, n) threshold secret sharing, and phase retrieval in the Fresnel domain. In the encryption process, after wavelet transform and Arnold transform of the target image, the ciphertext matrix can be first detected using a bucket detector. Based on a (t, n) threshold secret sharing algorithm, the measurement key used in the row scanning compressive ghost imaging can be decomposed and shared into two pairs of sub-keys, which are then reconstructed using two phase-only mask (POM) keys with fixed pixel values, placed in the input plane and transform plane 2 of the phase retrieval scheme, respectively; and the other POM key in the transform plane 1 can be generated and updated by the iterative encoding of each plaintext image. In each iteration, the target image acts as the input amplitude constraint in the input plane. During decryption, each plaintext image possessing all the correct keys can be successfully decrypted by measurement key regeneration, compression algorithm reconstruction, inverse wavelet transformation, and Fresnel transformation. Theoretical analysis and numerical simulations both verify the feasibility of the proposed method.
Shared Secrets: Motherhood and Male Homosexuality in Doppelgänger Narratives
Sencindiver, Susan Yi
2011-01-01
narratives. Enlisting Joseph Conrad’s short story, “The Secret Sharer,” among others, as both a paradigmatic yet self-conscious example, I examine the intersecting hotbed of these two strange bedfellows, motherhood and homosexuality, as well as the significance of gender in the male doppelgänger imaginary....
Neuroticism and Morning Cortisol Secretion: Both Heritable, But No Shared Genetic Influences
Riese, H; Rijsdijk, F.V.; Rosmalen, J.G.M.; Snieder, Harold; Ormel, J.
2009-01-01
Neuroticism is widely used as an explanatory concept in etiological research of psychopathology. To clarify what neuroticism actually represents, we investigated the phenotypic and genetic relationship between neuroticism and the morning cortisol secretion. In the current classic twin study, 125 fem
Neuroticism and Morning Cortisol Secretion : Both Heritable, But No Shared Genetic Influences
Riese, Harriette; Rijsdijk, Fruehling V.; Rosmalen, Judith G. M.; Snieder, Harold; Ormel, Johan
2009-01-01
Neuroticism is widely used as an explanatory concept in etiological research of psychopathology. To clarify what neuroticism actually represents, we investigated the phenotypic and genetic relationship between neuroticism and the morning cortisol secretion. In the current classic twin study, 125 fem
LIN Song; WEN Qiao-Yan; LIU Xiao-Fen
2009-01-01
In a recent paper[Yan F L et al.Chin.Phys.Lett.25(2008)1187],a quantum secret sharing the protocol between multiparty and multiparty with single photons and unitary transformations was presented.We analyze the security of the protocol and find that a dishonest participant can eavesdrop the key by using a special attack.Finally,we give a description of this strategy and put forward an improved version of this protocol which can stand against this kind of attack.
Chunguang Ma
2010-04-01
Full Text Available Recently, Numerous dynamic key management schemes have been proposed for WSN, and it has long-lived networks, more sustained security and survivability, such as SHELL and LCOK. But most of these schemes are greatly depend on some central nodes (gateways, if these nodes were compromised, there will be great threat to the whole networks security and survivability. In this paper, we proposed a Location-aware and secret share based dynamic key management scheme to effectively replace the compromised central node and enhance the security level of the network.
Neuroticism and Morning Cortisol Secretion: Both Heritable, But No Shared Genetic Influences
Riese, Harriette; Rijsdijk, Fruehling V.; Rosmalen, Judith G. M.; Snieder, Harold; Ormel, Johan
2009-01-01
Neuroticism is widely used as an explanatory concept in etiological research of psychopathology. To clarify what neuroticism actually represents, we investigated the phenotypic and genetic relationship between neuroticism and the morning cortisol secretion. In the current classic twin study, 125 female twin pairs (74 monozygotic and 51 dizygotic pairs) participated. For each participant, 4 different neuroticism scores were available to calculate a neuroticism composite score that was used in ...
分担有理函数的亚纯函数%Meromorphic Functions That Share Rational Functions
仇惠玲
2007-01-01
In this paper, the uniqueness of meromorphic functions is studied and the following result is proved:Let p(z) and q(z) be two coprime polynomials of degree n1 and n2 respectively, let f(z) and g(z) be two nonconstant transcendental meromorphic functions, and let n≥max{11,2n1+4n2+3} be a positive integer. If f n(z)f '(z) and gn(z)g'(z) share p(z)/q(z) CM, then f(z)=c1Q(z)eα(z), g(z)=c2Q-1(z)e-α(z), where c1,c2 are two constants, Q(z) is a rational function,and α(z) is a nonconstant polynomial satisfying(c1c2)n+1(Q'(z)/(Q(z)+α'(z))2≡-(p(z)/(q(z))2,or f(z)≡tg(z) for a constant t satisfying tn+1=1.%研究亚纯函数的惟一性,证明如下结果:设p(z)和q(z)分别为n1和n2次多项式且互素, f(z)和g(z)是两个超越亚纯函数,n≥max{11,2n1+4n2+3}是一个正整数,如果f n(z)f'(z),gn(z)g'(z)分担有理函数p(z)/q(z)CM,则f(z)=c1Q(z)eα(z),g(z)=c2Q-1(z)e-α(z),这里c1,c2是两个常数,Q(z)是一个有理函数,α(z)是一个非常数多项式,满足(c1c2)n+1(Q'(z)/(Q(z)+α'(z))2≡-(p(z)/q(z))2;或者f(z)≡tg(z),其中t是满足tn+1=1的常数.
Type VI secretion and bacteriophage tail tubes share a common assembly pathway
Yannick R Brunet; Hénin, Jérôme; Celia, Hervé; Cascales, Eric
2014-01-01
The Type VI secretion system (T6SS) is a widespread macromolecular structure that delivers protein effectors to both eukaryotic and prokaryotic recipient cells. The current model describes the T6SS as an inverted phage tail composed of a sheath-like structure wrapped around a tube assembled by stacked Hcp hexamers. Although recent progress has been made to understand T6SS sheath assembly and dynamics, there is no evidence that Hcp forms tubes in vivo. Here we show that Hcp interacts with TssB...
Secret-Sharing over Multiple-Antenna Channels with Transmit Correlation
Zorgui, Marwen
2015-01-07
We consider secret-key agreement with public discussion over Rayleigh fastfading channels with transmit correlation. The legitimate receiver and the eavesdropper are assumed to have perfect channel knowledge while the transmitter has only knowledge of the transmit correlation matrix. First, We derive the expression of the key capacity under the considered setup. Then, we show that the optimal transmit strategy achieving the key capacity consists in transmitting Gaussian signals along the eingenvectors of the channel covariance matrix. The powers allocated to each channel mode are determined as the solution of a numerical optimization problem that we derive. We also provide a waterfilling interpretation of the optimal power allocation. Finally, we develop a necessary and sufficient condition for beamforming to be optimal, i.e., transmitting along the strongest channel mode only is key capacity-achieving.
动态安全的多级门限多秘密共享方案%Multi-level threshold multi-secret sharing scheme with proactive security
邹惠; 王建东
2009-01-01
In multi-secret sharing schemes, the secrets can only be shared in the same level threshold. A multi-level threshold multi-secret sharing scheme based on bivariate polynomial and the intractability of the discrete logarithm was proposed. A bivariate polynomial can degenerate to different lower-order bivariate polynomial according to different thresholds. The scheme has the following characteristics: the secrets can be shared in the multiple level threshold; the multiple secrets can be shared in the same level threshold; the scheme is proactive secure, and the shadow of every participant can be renewed periodically.%在已有的多秘密共享方案中,存在只能在同一级门限下共享秘密的限制.基于离散对数问题的难解性,利用二元多项式,给出一种多级门限多秘密共享方案.二元多项式能在不同级门限共享中退化为不同的低阶的二元多项式,实现多级多秘密共享.该方案具有如下特点:在多级门限下共享秘密,在同级门限下可共享任意多个秘密;具有动态安全性,能定时更新成员的子秘密.
A New Loss-Tolerant Image Encryption Scheme Based on Secret Sharing and Two Chaotic Systems
Li Li
2012-04-01
Full Text Available In this study, we propose an efficient loss-tolerant image encryption scheme that protects both confidentiality and loss-tolerance simultaneously in shadow images. In this scheme, we generate the key sequence based on two chaotic maps and then encrypt the image during the sharing phase based on Shamir’s method. Experimental results show a better performance of the proposed scheme for different images than other methods from human vision. Security analysis confirms a high probability to resist both brute-force and collusion attacks.
Type VI secretion and bacteriophage tail tubes share a common assembly pathway.
Brunet, Yannick R; Hénin, Jérôme; Celia, Hervé; Cascales, Eric
2014-03-01
The Type VI secretion system (T6SS) is a widespread macromolecular structure that delivers protein effectors to both eukaryotic and prokaryotic recipient cells. The current model describes the T6SS as an inverted phage tail composed of a sheath-like structure wrapped around a tube assembled by stacked Hcp hexamers. Although recent progress has been made to understand T6SS sheath assembly and dynamics, there is no evidence that Hcp forms tubes in vivo. Here we show that Hcp interacts with TssB, a component of the T6SS sheath. Using a cysteine substitution approach, we demonstrate that Hcp hexamers assemble tubes in an ordered manner with a head-to-tail stacking that are used as a scaffold for polymerization of the TssB/C sheath-like structure. Finally, we show that VgrG but not TssB/C controls the proper assembly of the Hcp tubular structure. These results highlight the conservation in the assembly mechanisms between the T6SS and the bacteriophage tail tube/sheath.
基于LUC密码体制的动态多秘密共享方案%Dynamic Multi-secret Sharing Scheme Based on LUC Cryptosystem
张伟; 杜伟章
2015-01-01
On the basis of the existing secret sharing schemes based on LUC cryptosystem,this paper proposes a new dynamic multi-secret sharing scheme. The scheme does not need to build secure channel between secret dealer and members,and the members and secrets can be dynamically added and deleted. In the phase of secret recovery,cooperative members only need to submit shadow shares for designated combiner,and the verifier can verify the validity of shadow shares publicly. Thus the system does not need renew secret shares in sharing multiple secrets and multi-group multi-secret. The security of the scheme is proved in the random oracle model, under assumption of the discrete logarithm problem,the result shows that this scheme is semantic security, and in the aspect of calculation, security, the overall performance is superior to the traditional secret sharing scheme.%在现有基于LUC密码体制的秘密共享方案基础上，提出一种新的动态多秘密共享方案。该方案无需在秘密分发者与成员之间建立安全信道，就能对成员和秘密进行动态添加或删除。在秘密重构过程中，合作成员只需向指定生成者提交影子份额，且验证者可对影子份额进行公开验证，从而使得系统无需更新成员的秘密份额即可实现一次性共享多个秘密和多组秘密。通过随机预言机模型对该方案进行验证，结果表明，在离散对数问题的假设下该方案是语义安全的，并且在计算量、安全性、总体性能方面均优于传统秘密共享方案。
BIVARIATE POLYNOMIAL BASED SECRET SHARING TECHNOLOGY STUDY%基于二元多项式的秘密分享技术研究
唐聃; 舒红平
2012-01-01
At present most secret sharing schemes follow the realization idea of classic Shamir scheme, namely the unary polynomial based (k, n) threshold scheme. Such schemes inherit many advantages of Shamir scheme, such as simple thought, easy implementation, harmony of perfection and idealness and so on. However, still there is a defect in these schemes that their access structure is not rich enough, so that the popularization of secret sharing technology in practical applications is seriously limited. In view of this situation, the paper proposes a bivariate polynomial based secret sharing scheme. Besides possessing the various advantages of Shamir scheme, the access structure of the new scheme is greatly enriched. In addition, the new scheme can easily be introduced to image secret sharing, audio secret sharing as well as other fields.%当前大多数秘密分享方案的设计沿用了经典Shamir方案的实现思路,即基于一元多项式的(k,n)门限方案.此类方案继承了Shamir方案的诸多优点,如思路简洁便于实现、兼有完备性(Perfect)和理想性(Ideal)等.然而,这一类方案也有着准入结构不够丰富的缺陷,极大地限制了秘密分享技术在实际应用中的推广.针对这一情况,提出一种基于二元多项式的秘密分享方案,该方案兼有Shamir方案的诸多优点,而准入结构又得到了极大的丰富.此外,新方案很容易推广到图像秘密分享、音频秘密分享等领域.
Liapkov, B G
1978-01-01
Feeding of rats on a ration with an excessive content of sunflower-oil (60 per cent of the total calorific value of the ration) for a period of 30 days resulted in lowering the rate of the apoproteins, prolipoproteins synthesis in the liver and in their loading with triglycerides and cholesterol. As a consequence of this it diminished secretion of endogenously formed tryglycerides and cholesterol from the liver into the blood and a changed lipid composition of lipoproteins of a very low density in the blood.
RESEARCH ON SECRET SHARING OF IMAGE BASED ON CODING THEORY%基于编码理论的图像秘密分享技术研究
唐聃; 王晓京
2013-01-01
图像的秘密分享是信息安全技术领域具有独特吸引力的研究问题。经过近20年的发展，图像秘密分享已经发展成为一个相对独立的技术领域，但却远没有达到完善的程度。当前大多数图像秘密分享方案均采用了Shamir方案的拉格朗日插值法作为分享方案的核心思想，但是这对于数据量巨大的图像而言无疑会大大降低计算的效率和系统的实用性。基于编码和秘密分享的内在联系，提出一种基于编码技术的图像秘密分享方案。除了具备大多数基于拉格朗日插值法图像秘密分享方案的优点外，新方案算法复杂度显著降低且具有思路简单、容易实现和便于扩展到视频音频领域等特点，有着更加明显的实用价值；此外，基于编码的图像秘密分享系统的实现也从一个侧面证实了编码与秘密分享在本质上的联系。%Secret sharing of image is a research subject with unique attraction in information security technology filed .After developing almost 20 years, secret sharing of image has become a relatively independent technical domain , but far from perfect level .Most of the current secret sharing scheme for image uses Lagrange interpolation of Shamir ’ s scheme as their core idea; however for images with huge amount of data, this will greatly reduce the computational efficiency and system availability .According to internal relationship between the coding theory and the secret sharing technology , in the paper we propose a coding theory-based secret scheme of image .In addition to having the advantages which most secret sharing schemes for image based on Lagrange interpolation have , the new method reduces the computational complexity remarkably and has the features such as simple idea , easy to implement , convenient in extending to the field of video and audio , etc., therefore has more apparent practical value .Besides, the realisation of the coding
Proactive Secret Sharing Scheme Based on ECC%一种基于ECC的动态秘密共享方案
范畅; 茹鹏
2012-01-01
Secret keepers have to face some tasks of key generation, distribution and verification in many of secret sharing schemes with trusted center. Members have difficulty in determining if the recovered secret is valid when the dealer cheats. Furthermore, those schemes are hard to achieve real proactive property. For the purpose of solving the problems, we proposed a distributed proactive secret sharing scheme based on elliptic curve cryptosystems without the trusted center. Anyone can check sub - shares provided by any members. The proactive property can be well implemented in solving secret updating and sub - shares reusing based on secure multi - party computation simulation method. Finally, the security and efficiency were analyzed in the paper. Experiments prove that; this scheme is of higher theoretical innovation and practical engineering value in terms of safety improvement, efficiency and feasible.%许多秘密共享方案需要一个可信方参与,并完成掌管秘密及子密钥的产生、分发和验证工作,一旦可信方出现欺诈或故障,成员很难判断恢复秘密的真伪,既没有解决秘密更新和子密钥复用问题,更不具有秘密的动态更新和生命期特性.为此提出了基于椭圆曲线密码体制的秘密共享方案,具有分布式和动态特性,不需要第三可信方参与,并解决了秘密更新和子密钥复用问题；利用安全多方计算的仿真方法实现；经实验证明:动态方案在安全性方面有所提高,在效率方面可行,具有较高的理论创新和实践工程价值.
Quantum secret sharing with quantum graph states%基于量子图态的量子秘密共享∗
梁建武; 程资; 石金晶; 郭迎
2016-01-01
Quantum secret sharing is an important way to achieve secure communications, which has critical applications in the field of information security for its physical properties. According to the perspective of the practical applications, improving the confidentiality and integrity of secret sharing schemes is a good method to increase the security and reliability of communications. In this paper, we propose a quantum secret sharing scheme based on generator matrix segmentation and the structural features of quantum graph states. The security of the secure secret sharing scheme is guaranteed by the pattern of transferring information by stabilizers, scalability of the information and new recovery strategy provided by the entanglement of the related graph states. It puts forward an effective solution to the problem of matrix cycle period, where some numbers without the primitive element cannot construct the generation matrix. First of all, the physical properties of quantum bits (qubits), such as uncertainty principle, no-cloning theorem and indistinguishability, not only optimize the classical schemes but also ensure the absolute safety of communication. Secondly, the application of matrix segmentation makes secret information has better scalability. It improves the coding diversity and the diﬃculty in deciphering. Thirdly, the favorable entanglement properties and mature experiment preparation techniques of graph states provide an approach to the practical applications. The superiority of the yielded graph states is described in graphical fashion with an elegant stabilizer. Fourthly, the shuﬄing operation can ensure the independence of the message among participants. Therefore, Eve can not obtain any useful information by measuring randomly. Two group-recovery protocols are proposed to show the secret recovering processing through rebuilding sub-secrets among legal cooperative participants. In the scheme design, the dealer extracts the classical secret information
Sahasranand, K R
2010-01-01
Almost all known secret sharing schemes work on numbers. Such methods will have difficulty in sharing graphs since the number of graphs increases exponentially with the number of nodes. We propose a secret sharing scheme for graphs where we use graph intersection for reconstructing the secret which is hidden as a sub graph in the shares. Our method does not rely on heavy computational operations such as modular arithmetic or polynomial interpolation but makes use of very basic operations like assignment and checking for equality, and graph intersection can also be performed visually. In certain cases, the secret could be reconstructed using just pencil and paper by authorised parties but cannot be broken by an adversary even with unbounded computational power. The method achieves perfect secrecy for (2, n) scheme and requires far fewer operations compared to Shamir's algorithm. The proposed method could be used to share objects such as matrices, sets, plain text and even a heterogeneous collection of these. S...
李铁牛; 李红达
2010-01-01
Along with the distributed computation becoming more and more popular,security mechanisms of the distributed RSA key computation to enhance the strength of distributed authentication and data privacy have been developed quite a lot. However,most of them are the solutions for parties with traditional types like being semi-honest or malicious. We propose a rational approach to dealing with the distributed computation of the RSA private key based on the secret sharing of the Euler totient function over polynomials,in which each player evolved is selfish and motivated to gain interest as mush as possible. The achievement is that it is a Nash equilibrium that each player follows the execution of the prescribed protocol. And the strategy survives the iterated deletion of weakly dominated strategies%随着分布式计算的发展,分布式计算环境中的安全性问题变得越来越突出.基于RSA算法的分布式认证和分布式数据加密等安全性机制也取得了长足的发展.不过,这些机制中大部分是基于传统密码协议中参与者类型的假设:半诚实或恶意的.本文从假设参与者是理性的这一视角出发,设计了基于RSA欧拉函数秘密分享的RSA私钥的分布式计算协议.协议中所有的参与者均是理性的,他们以自我利益为驱动.所有的参与者均采取遵守协议的执行这一策略形成了纳什均衡,并且该策略是不能严格劣势剔除的.
Discovering and Sharing of Secret Architectures: the Hidden Tomb of the Pharaoh of El-Khasneh Jordan
Malinverni, E. S.; Pierdicca, R.
2017-02-01
The documentation of the archaeological heritage through 3D models to know ancient findings, has become a common practice within the international panorama. Using minimal hardware, as well as its ease of use in almost every environmental condition, make 3D sampling solutions based on Multiple View Stereo (MVS) matching and Structure from Motion techniques ideal for on-site documentation of excavations or emergencies. Moreover, the availability of inexpensive platforms for web-based visualization represents great benefit in the field of archaeology, where generally the low budged and the limitation of more complex instruments are a must. The case study presented in these pages, experienced in Petra, Jordan, moves towards this direction. In the close proximity of the El- Khasneh façade, is situated an excavation where two entrance, well preserved, give access to the Tomb of Pharaoh. The documentation described in these pages has the twofold objective of providing the research community with a priceless dataset, acquired for one of the most important heritage of the world that is partially still unknown and to share on line these computations. This work confirms how cultural heritage documentation and dissemination of architectural rests, that are important for tourism and their interactive visualization, can strongly benefit from the creation of 3D models and their sharing on the web. This particular archaeological setting is an interesting base for investigation, given the complexity of the structure and its precarious condition.
Mayo, David J.
1998-01-01
The rational suicide paradigm is contrasted with the traditional view of the mental health professions. Historical background on suicide in western civilization is supplied and the concept of rationality elucidated. Parallels between the questions of refusing life-prolonging therapy and rational suicide are discussed, as are reasons for suicide.…
Angeles, Jorge
1988-01-01
A rational study of kinematics is a treatment of the subject based on invariants, i.e., quantities that remain essentially unchanged under a change of observer. An observer is understood to be a reference frame supplied with a clock (Truesdell 1966). This study will therefore include an introduction to invariants. The language of these is tensor analysis and multilinear algebra, both of which share many isomorphic relations, These subjects are treated in full detail in Ericksen (1960) and Bowen and Wang (1976), and hence will not be included here. Only a short account of notation and definitions will be presented. Moreover, definitions and basic concepts pertaining to the kinematics of rigid bodies will be also included. Although the kinematics of rigid bodies can be regarded as a particular case of the kinematics of continua, the former deserves attention on its own merits for several reasons. One of these is that it describes locally the motions undergone by continua. Another reason is that a whole area of ...
Yeo, Tien Ee Dominic; Chu, Tsz Hang
2017-09-01
Social media present opportunities and challenges for sexual health communication among young people. This study is one of the first to examine the actual use of Facebook for peer communication of sexual health and intimate relations. Content analysis of 2186 anonymous posts in a "sex secrets" Facebook page unofficially affiliated with a Hong Kong University shows gender balance among posters, inclusiveness of sexual minorities, and frequent sharing of personal experiences in storytelling or advice seeking. The findings illuminate young people's health concerns regarding condom use, avoiding pain, birth control, sexually transmitted infections, and body appearance. Relational concerns found entailed sexual practices, expectations, and needs-predominantly within dating relationships and include not wanting to have sex. Supportive communication among users was prevalent. A majority of posts involved advice solicitation in the form of request for opinion or information (30.38%), request for advice (13.68%), situation comparison (5.40%), or problem disclosure (9.97%). Comments to the advice-seeking posts were mostly supportive (69.49%); nonsupportive responses (unsolicited messages and gratuitous humor) were concentrated with ambiguous advice solicitations. These findings hold implications for understanding self-disclosure of intimate concerns within social networks, and attuning sexual health intervention on social media to young people's actual needs and advice preferences.
Hougaard, Jens Leth; Moreno-Ternero, Juan D.; Østerdal, Lars Peter Raahave
The standard problem of adjudicating conflicting claims describes a situation in which a given amount of a divisible good has to be allocated among agents who hold claims against it exceeding the available amount. This paper considers more general rationing problems in which, in addition to claims......, there exist baselines (to be interpreted as objective entitlements, ideal targets, or past consumption) that might play an important role in the allocation process. The model we present is able to accommodate real-life rationing situations, ranging from resource allocation in the public health care sector...... to international protocols for the reduction of greenhouse emissions, or water distribution in drought periods. We define a family of allocation methods for such general rationing problems - called baseline rationing rules - and provide an axiomatic characterization for it. Any baseline rationing rule within...
基于 Shamir 秘密共享的云端多副本审计%Multiple-replica auditing in clouds using Shamir secret sharing
田晖; 陈羽翔; 黄永峰
2016-01-01
For auditing the integrity of multiple-replica in clouds,a public auditing scheme based on Shamir secret sharing was presented.The scheme can generate diverse data tags for different replicas of a given file using Shamir-secret-sharing algorithm,which is helpful for avoiding possible attacks from cloud service provider (CSP)and locating errors while the CSP does not exactly store all required replicas.Further,the scheme support batch auditing for multiple-replicas using Boneh-Lynn-Shacham (BLS)signature and bilinear maps,which can cut down times of interactions between the CSP and the auditor,and reduce communication costs.Moreover,random masks were introduced in user′s data preprocessing and auditing process to avert conspiracy attack of the CSP and prevent privacy leakage. The security of the presented scheme was proved in theory,and the auditing performance was experi-mentally compared with that of the previous work.The experimental results demonstrate that the pro-posed scheme can effectively achieve secure auditing for multiple-replica in clouds,and outperforms the existing methods on both time and space costs.%针对云端多副本审计问题，提出了一种基于 Shamir 秘密共享的审计方案。该方案利用 Shamir 秘密共享算法为同一数据文件的所有副本生成不同的数据标签，以防范云服务提供商的多种攻击，且根据该算法特性生成的聚合标签能有助于实现云服务提供商未完全持有全部副本数据时的出错定位；利用 BLS （Boneh-Lynn-Shacham）签名和双线性映射技术实现了多副本的批量审计，避免了云服务提供商与审计者之间的多次交互，从而降低了审计过程中的通信开销；通过在用户数据预处理阶段引入随机掩码实现了对合谋攻击的防范，并在审计过程中应用随机掩码避免了用户隐私的泄漏。对提出方案的安全性进行了理论证明，并与已有方法在性能方面进行了比较和实
Blackett, S.A. [Univ. of Auckland (New Zealand). Dept of Engineering Science
1996-02-01
Numerical analysis is an important part of Engineering. Frequently relationships are not adequately understood, or too complicated to be represented by theoretical formulae. Instead, empirical approximations based on observed relationships can be used for simple fast and accurate evaluations. Historically, storage of data has been a large constraint on approximately methods. So the challenge is to find a sufficiently accurate representation of data which is valid over as large a range as possible while requiring the storage of only a few numerical values. Polynomials, popular as approximation functions because of their simplicity, can be used to represent simple data. Equation 1.1 shows a simple 3rd order polynomial approximation. However, just increasing the order and number of terms included in a polynomial approximation does not improve the overall result. Although the function may fit exactly to observed data, between these points it is likely that the approximation is increasingly less smooth and probably inadequate. An alternative to adding further terms to the approximation is to make the approximation rational. Equation 1.2 shows a rational polynomial, 3rd order in the numerator and denominator. A rational polynomial approximation allows poles and this can greatly enhance an approximation. In Sections 2 and 3 two different methods for fitting rational polynomials to a given data set are detailed. In Section 4, consideration is given to different rational polynomials used on adjacent regions. Section 5 shows the performance of the rational polynomial algorithms. Conclusions are presented in Section 6.
Macmillan, C. J. B.
1985-01-01
The recognition of teaching as a special relationship among individuals is currently being overlooked in much contemporary educational research and policymaking. The author examines the philosophy of rationality in teaching and relates it to the educational vision presented in George Orwell's novel, "Nineteen Eighty-Four." (CB)
Lam, Chi-Ming
2014-01-01
Nowadays, there is still a widely held view that the Chinese and Western modes of thought are quite distinct from each other. In particular, the Chinese mode of thought derived from Confucianism is considered as comparatively less rational than the Western one. In this article, I first argue that although the analogical mode of argumentation,…
The Rationality of Alcoholics Anonymous and the Spirituality of Rational Emotive Behavior Therapy.
Velten, Emmett
1996-01-01
Argues that Alcoholics Anonymous (AA) and Rational Emotive Behavior Therapy (REBT) share important rational objectives and numerous cognitive-behavioral methods. Both emphasize a philosophical shift as a principal ingredient for change. Provides definitions of rationality and spirituality and explains how REBT and smart recovery are spiritual…
The Rationality of Alcoholics Anonymous and the Spirituality of Rational Emotive Behavior Therapy.
Velten, Emmett
1996-01-01
Argues that Alcoholics Anonymous (AA) and Rational Emotive Behavior Therapy (REBT) share important rational objectives and numerous cognitive-behavioral methods. Both emphasize a philosophical shift as a principal ingredient for change. Provides definitions of rationality and spirituality and explains how REBT and smart recovery are spiritual…
方世敏; 陈洁
2013-01-01
目前，海南省旅游业总体规模不断扩大，且创汇效益显著，但其进一步的发展很大程度上取决于其产业结构的合理性。从Shift-Share方法为视角，分析了海南省旅游产业部门的现状。结果表明：餐饮、购物、游览部门结构效益相对较优，长途交通、娱乐、市内交通和邮电通讯部门不具有区域竞争力，住宿和其他服务结构效益不佳，可从优、劣势部门各自的层面采取对应措施，同时还应加强各部门之间的协作发展，以进一步促进旅游产业结构优化。%The overall scale of tourism industry in Hainan province is expanding,and its foreign exchange earing effect is significant,but further development much depends on the rational tourism industrial structure. Consequently,this article uses Shift-Share Method to make analysis of problems in the structure.The results show that the structure benefit of catering, shopping and tour sector is relatively better;the long -distance transportation,entertainment,city traffic and telecommunication sector is deficient in regional competition;accommodation and other service sectors have weak foundation and poor efficiency. On this basis,it can take corresponding measures from the aspect of advantage sector and inferior sector,and should also strengthen the cooperation between various sectors to rationalize the structure of tourism industry.
Georg Spielthenner
2007-01-01
Full Text Available Valuations are ubiquitous. We may be for or against genetically modified food; we find some politicians irresponsible; we prefer Beethoven to rock ‘n’ roll or vice versa; some enjoy bird-watching while others find it boring; and we may think that we have to tighten up on green-house gas emissions. Valuing is pervasive and often we are not even aware that we are valuing. However, many of ourvaluations are ill grounded and rationally defective. They are frequently based on misinformation, sloppy thinking, prejudice, and are biased in many ways as psychological research shows. For this reason there is widespread agreement among phi-losophers that we need an account of substantive valuational rationality, both for the theory of practical reasoning and for ethics as well. My main objectin this paper is to outline such an account and to present a principle that allows a non-technical rational criticism of valuations
Ballester Pla, Coralio
2012-03-01
Full Text Available The observation of the actual behavior by economic decision makers in the lab and in the field justifies that bounded rationality has been a generally accepted assumption in many socio-economic models. The goal of this paper is to illustrate the difficulties involved in providing a correct definition of what a rational (or irrational agent is. In this paper we describe two frameworks that employ different approaches for analyzing bounded rationality. The first is a spatial segregation set-up that encompasses two optimization methodologies: backward induction and forward induction. The main result is that, even under the same state of knowledge, rational and non-rational agents may match their actions. The second framework elaborates on the relationship between irrationality and informational restrictions. We use the beauty contest (Nagel, 1995 as a device to explain this relationship.
La observación del comportamiento de los agentes económicos tanto en el laboratorio como en la vida real justifica que la racionalidad acotada sea un supuesto aceptado en numerosos modelos socio-económicos. El objetivo de este artículo es ilustrar las dificultades que conlleva una correcta definición de qué es un agente racional (irracional. En este artículo se describen dos marcos que emplean diferentes metodologías para analizar la racionalidad acotada. El primero es un modelo de segregación espacial donde se contrastan dos metodologías de optimización: inducción hacia atrás y hacia adelante. El resultado principal es que, incluso con el mismo nivel de conocimiento, tanto agentes racionales como irracionales podrían coincidir en sus acciones. El segundo marco trabaja sobre la relación entre irracionalidad y restricción de información. Se utiliza el juego llamado “beauty contest” (Nagel 1995 como mecanismo para explicar dicha relación.
Proactive Threshold RSA Signature Scheme Based on Polynomial Secret Sharing%基于多项式秘密共享的前摄性门限RSA签名方案
徐甫
2016-01-01
现有可证明安全的前摄性门限RSA签名方案均依赖加性秘密共享方法，存在每次签名均需所有成员参与，易暴露合法成员的秘密份额，签名效率低下等问题。该文以Shoup门限签名为基础，提出一种基于多项式秘密共享的前摄性门限RSA签名方案，并对其进行了详细的安全性及实用性分析。结果表明，在静态移动攻击者模型中，该方案是不可伪造的和稳健的，与现有同类方案相比，其通信开销更低，运算效率更高。%All the existing provable secure proactive threshold RSA signature schemes rely on additive secret sharing, in which all players have to cooperate to produce a signature, valid players’ secret shares may be exposed, and the computing efficiency is too low. Based on Shoup’s threshold RSA signature scheme, a proactive threshold RSA signature scheme is proposed by using polynomial secret sharing, and its security and practicability are analyzed. Results show that the proposed scheme is unforgeable and robust under the model of static mobile adversary, and compared with the existing comparable schemes, its communication overhead is lower and computing efficiency is higher.
Binmore, Ken
2008-01-01
It is widely held that Bayesian decision theory is the final word on how a rational person should make decisions. However, Leonard Savage--the inventor of Bayesian decision theory--argued that it would be ridiculous to use his theory outside the kind of small world in which it is always possible to ""look before you leap."" If taken seriously, this view makes Bayesian decision theory inappropriate for the large worlds of scientific discovery and macroeconomic enterprise. When is it correct to use Bayesian decision theory--and when does it need to be modified? Using a minimum of mathematics,
Rationalization: A Bibliography.
Pedrini, D. T.; Pedrini, Bonnie C.
Rationalization was studied by Sigmund Freud and was specifically labeled by Ernest Jones. Rationalization ought to be differentiated from rational, rationality, logical analysis, etc. On the one hand, rationalization is considered a defense mechanism, on the other hand, rationality is not. Haan has done much work with self-report inventories and…
Rational inattention or rational overreaction?
Browning, Martin; Hansen, Lars Gårn; Smed, Sinne
We investigate differences in how consumers of fish react to health information in the mass media. We specify a dynamic empirical model that allows for heterogeneity in all basic parameters of consumer behavior as well as in how consumers react to information. We estimate the model using a unique...... houshold panel tracking consumption, prices, news stories and media habits over 24 quarters. We fi nd that the consumers most likely to be ’rationally ignorant’ of health effects react more dramatically to health news than the consumers who most likely are well informed....
Rational inattention or rational overreaction?
Browning, Martin; Hansen, Lars Gårn; Smed, Sinne
We investigate differences in how consumers of fish react to health information in the mass media. We specify a dynamic empirical model that allows for heterogeneity in all basic parameters of consumer behavior as well as in how consumers react to information. We estimate the model using a unique...... houshold panel tracking consumption, prices, news stories and media habits over 24 quarters. We fi nd that the consumers most likely to be ’rationally ignorant’ of health effects react more dramatically to health news than the consumers who most likely are well informed....
可验证多次使用动态门限大秘密共享方案%Verifiable Multi-Use Dynamic Threshold Large Secret Sharing Scheme
常利伟; 郑世慧; 邢友松; 金磊; 杨义先
2015-01-01
For the efficiency and security problems of large secret sharing, a verifiable multi-use dynamic thres hold large secret sharing scheme was put forward. To improve the efficiency, the large secret is di-vided and represented as a matrix over smaller finite field, and the two-variable one-way function is also utilized;to enhance security, the thres hold modification method is slightly expanded and the elliptic curve discrete logarithm problem is employed. By analysis, this new scheme not only is high-efficiency, but also can prevent dishonest participants from cheating. Meanwhile, the secret shadows can always be kept secret and need not to be renewed in the process of reconstruction. Especially, when the mutual trust varies or the number of the participants belonging to an organization fluctuates, the threshold value will be adjusted by at least t credible participants in time.%针对大秘密共享存在效率和安全方面的不足,提出一个可验证多次使用动态门限大秘密共享方案. 为了提高效率,将大秘密分解,且表示为较小有限域上的矩阵,并利用了二元单向函数. 为了增强安全性,推广门限动态调整方法,利用了椭圆曲线群上离散对数. 理论分析结果表明,该方案不仅存储等效率大大提高,还能抵抗不诚信参与者攻击,且重建过程中秘密份额始终保密无须更新. 尤其当参与者信任发生变化或参与者人数变动时,门限值能够被t个可信参与者及时调整.
What Information Theory Says about Bounded Rational Best Response
Wolpert, David H.
2005-01-01
Probability Collectives (PC) provides the information-theoretic extension of conventional full-rationality game theory to bounded rational games. Here an explicit solution to the equations giving the bounded rationality equilibrium of a game is presented. Then PC is used to investigate games in which the players use bounded rational best-response strategies. Next it is shown that in the continuum-time limit, bounded rational best response games result in a variant of the replicator dynamics of evolutionary game theory. It is then shown that for team (shared-payoff) games, this variant of replicator dynamics is identical to Newton-Raphson iterative optimization of the shared utility function.
李瑞林; 陈够喜; 武雪芹
2015-01-01
Greater distortion of image steganography was caused by applying the simple least significant bit (LSB) to embed se‐cret information directly in the traditional technology .Therefore ,an efficient verifiable secret sharing method was proposed .A bit sequence was taken as the input of secret sharing which was generated using differential Huffman lossless compression of se‐cret image .The polynomial interpolation and certified value formula were improved .As a result ,the quality of the stego image and the verifiability were enhanced using the technology .Theoretical analysis and experimental results show that high quality of stego image with efficient verifiability and security can be obtained through the scheme .%在传统方案中，直接采用简单最低有效位（LSB）嵌入秘密信息，导致隐写图像失真度较高，为此提出一种高效的可验证秘密共享方案。引入差分哈夫曼无损压缩思想，将产生的比特序列作为秘密共享的输入；通过改进插值多项式和认证值计算公式，增强隐写图像的质量并提高其可验证性。理论分析与实验结果表明，应用该方案可得到高质量的隐写图像，其具有高效可验证性和安全性。
On rationally supported surfaces
Gravesen, Jens; Juttler, B.; Sir, Z.
2008-01-01
We analyze the class of surfaces which are equipped with rational support functions. Any rational support function can be decomposed into a symmetric (even) and an antisymmetric (odd) part. We analyze certain geometric properties of surfaces with odd and even rational support functions....... In particular it is shown that odd rational support functions correspond to those rational surfaces which can be equipped with a linear field of normal vectors, which were discussed by Sampoli et al. (Sampoli, M.L., Peternell, M., Juttler, B., 2006. Rational surfaces with linear normals and their convolutions...... with rational surfaces. Comput. Aided Geom. Design 23, 179-192). As shown recently, this class of surfaces includes non-developable quadratic triangular Bezier surface patches (Lavicka, M., Bastl, B., 2007. Rational hypersurfaces with rational convolutions. Comput. Aided Geom. Design 24, 410426; Peternell, M...
REVIEW OF DIGITAL IMAGE SHARING BY DIVERSE IMAGE MEDIA
Mayuri Sonkusare
2015-10-01
Full Text Available A natural-image-based VSS scheme (NVSS scheme that shares secret images. A natural-imagebasedsecret image sharing scheme (NSISS that can share a color secret image over n - 1 arbitrary naturalimages and one noise-like share image. Instead of altering the contents of the natural images, the encryptionprocess extracts feature images from each natural image. In order to protect the secret image from transmissionphase. (n, n - NVSS scheme shared secret image over n-1 natural share. The natural shares will be digital imageand printed image. By extracting the features of natural shares we can prepare noise-like share. After thatencryption carried out with noise-like share and secret image. Propose possible ways to hide the noise like shareto reduce the transmission risk problem for the share. In this paper Initially Feature Extraction process has beenperformed for Natural Shares. Here Digital image and Printed image have been used as Natural Shares. Withthat extracted features secret image will be encrypted by (n, n - NVSS scheme where process carried by (n-1natural shares. This Encrypted result will be hided using Share-Hiding Algorithm where generated the QR code.In the Recovering of the secret image will be done by Share Extraction Algorithm and also decryptionalgorithm. Finally the secret image with all pixels has been obtained. This proposed possible ways to hide thenoise like share to reduce the transmission risk problem for the share.
Hougaard, Jens Leth; Moreno-Ternero, Juan D.; Østerdal, Lars Peter Raahave
2013-01-01
We introduce a new operator for general rationing problems in which, besides conflicting claims, individual baselines play an important role in the rationing process. The operator builds onto ideas of composition, which are not only frequent in rationing, but also in related problems...... such as bargaining, choice, and queuing. We characterize the operator and show how it preserves some standard axioms in the literature on rationing. We also relate it to recent contributions in such literature....
Luz Helena Guamanzara Torres
2013-01-01
Full Text Available This paper provides a review of the book The Law of Secrets, of the author Juan Carlos Martínez-Villalba Riofrío studying the secrets and how law does protect. To this end, the author has analyzed the general theory of secrecy, secrets and methodology, its overall rating, essential elements and their different legal dimensions, the secret as a subjective right. It also establishes that professional secrecy is protected by constitutional principles such as the right to privacy.
Secrets Shared: A Conversation with Francisco Jimemez.
Barrera, Rosalinda B.
2003-01-01
Presents an interview with Francisco Jimenez. Notes that he recently received the Tomas Rivera Mexican American Book Award for his authorship of "Breaking Through." Discusses his works and new ideas for future writing. (SG)
林志扬; 陈东灵
2011-01-01
In order to enhance team members' will to sharing knowledge, through using evolutionary game theory,this paper analyzed the inherent mechanism and dynamic evolutionary process of knowledge sharing in knowledge team. The results show that the factors which affect knowledge sharing in knowledge team included knowledge owning amount gap, risk coefficient, knowledge-sharing degree, proportion of complementary knowledge, incentive coefficient, cooperative influencing degree and so on, by adjusting the size of these parameters, can effectively improve the probability of knowledge-sharing strategy which knowledge team members chose.%为提高知识团队成员共享知识的意愿,通过运用演化博弈论,对知识团队知识共享的内在机理与动态演化过程进行了分析.结果表明,影响知识团队知识共享的因素有知识员工的知识拥有量差距、风险系数、知识共享度、互补性知识比例、激励系数、协同性影响程度等,通过调整这些参数的大小,可以有效提高知识团队成员选择知识共享策略的概率.
Telling stories: keeping secrets.
Jensen, Joan M
2009-01-01
This article addresses the reticence of some farm women to share their experiences with historians and how that desire to keep secrets collides with the desire by scholars to tell the stories of these women. It argues that scholars must continue to struggle with the issue of which stories to tell publicly and which to keep private. The author discusses her own experience telling stories about rural women in the 1970s and the need to give voice to the heritage of rural women, especially of groups that have feared revealing their experiences. She offers examples of historians of rural women who have successfully worked with formerly silenced populations and urges historians to continue to tell stories about these lives, to reevaluate what has been already learned, to ask new questions, and to discuss which secrets need to be shared.
石乐义; 贾聪; 宫剑; 刘昕; 陈鸿龙
2016-01-01
针对资源受限的 RFID 标签，结合伪随机数和共享秘密机制，该文提出一种基于散列函数的轻量级双向认证协议，实现了后端数据库、阅读器和标签之间的双向认证。详细分析了双向认证协议的抗攻击性能和效率性能，并基于BAN逻辑分析方法对协议模型进行了形式化证明。理论分析表明，该文提出的认证协议能够实现预期安全目标，抗攻击性能好，认证执行效率高且标签开销小，适用于大数量的RFID应用。%Concerning the resource-limited RFID tags, this paper presents a lightweight mutual authentication scheme based on Hash function, combining with the pseudo-random number and shared secret mechanisms, and implements the mutual authentication among the end database, reader and the tags. The anti-attack performance and the overhead of the scheme are analyzed in detail. Afterwards, the protocol security model is formalized using BAN logical analysis method. Theoretical analysis shows that the proposed authentication scheme could achieve the desired security goals, has good anti-attack performance and high efficiency. It can be applied to big population RFID since its low overhead for RFID tags.
Figueiredo, Newton; Vieira, Marco Antonio [Newmar Energia, Rio de Janeiro, RJ (Brazil). E-mail: newmar@dormain.com.br
1999-07-01
This paper presents an overview of the present status of the Brazilian electric power sector, aiming a near future introduction to the shared power concept. The paper recommends some actions for the energy distribution, using and availability in a fast way, which contributes for the improvement of Brazilian products competitive power.
Determinants of Actor Rationality
Ellegaard, Chris
Industrial companies must exercise influence on their suppliers (or supplier actors). Actor rationality is a central theme connected to this management task. In this article, relevant literature is studied with the purpose of shedding light on determinants of actor rationality. Two buyer......-supplier relations are investigated in a multiple case study, leading to the proposal of various additional factors that determine and shape actor rationality. Moreover a conceptual model of rationality determinants in the buyer-supplier relation is proposed, a model that may help supply managers analyse...
Standby Gasoline Rationing Plan
None
1980-06-01
The final rules adopted by the President for a Standby Gasoline Rationing Plan are presented. The plan provides that eligibility for ration allotments will be determined primarily on the basis of motor vehicle registrations, taking into account historical differences in the use of gasoline among states. The regulations also provide authority for supplemental allotments to firms so that their allotment will equal a specified percentage of gasoline use during a base period. Priority classifications, i.e., agriculture, defense, etc., are established to assure adequate gasoline supplies for designated essential services. Ration rights must be provided by end-users to their suppliers for each gallon sold. DOE will regulate the distribution of gasoline at the wholesale level according to the transfer by suppliers of redeemed ration rights and the gasoline allocation regulations. Ration rights are transferable. A ration banking system is created to facilitate transfers of ration rights. Each state will be provided with a reserve of ration rights to provide for hardship needs and to alleviate inequities. (DC)
Irrational Rationality of Terrorism
Robert Nalbandov
2013-12-01
Full Text Available The present article deals with the ontological problem of applying the rational choice frameworks to the study of terrorism. It testing the application of the rational choice to the “old” (before the end of the Cold War and the “new” (after the end of the Cold War terrorisms. It starts with analyzing the fundamentals of rationality and applies it at two levels: the individual (actors and group (collective via two outlooks: tactical (short-term and strategic (long-term. The main argument of the article is that while the “old” terrorism can be explained by the rational choice theory its “new” version represents a substantial departure from rationality.
Multiuser-based Gray-level Watermarking Sharing System
Bin Luo
2009-12-01
Full Text Available A novel watermarking sharing system having the ability of sharing gray-level secret images with multi-user is proposed. Multiple-based number system is used to split the secret into n meaningless shares, each share is embedded into respective cover image with controlled distortion and to be assigned to each user afterwards. The architecture of the proposed watermarking system is an open issue, which means the system is easy to be implemented according to the purposes and concerns of the users. The main feature of the proposed system is sharing a secret of gray-level image among multi-users; another application of such system is ownership verification. To reveal the secret, the necessary amount of shares has to be presented. That is, the secret can be recovered even if some shares were lost. Simulation results show that the recovered secret has robustness against a wide range of imaging processing operations.
基于秘密共享的具有签名功能的电子取证方案*%Forensic Investigation Based on Secret Sharing and Digital Signature
李想; 范玉妹
2013-01-01
调查取证与隐私保护存在冲突，如何实现既能取得与法律客观性保持一致的电子证据又能保护或避免披露无关用户的数据隐私变得日趋重要。针对这一问题，Hou et al提出了一类基于加密算法的电子取证方案，将取证关键词与被调查数据进行加密，再将两者的密文进行搜索匹配，最后解密匹配到的数据密文进行取证调查。由于复杂的加解密过程，该类方案计算复杂度高、处理时间长、取证效率低。为了提高取证效率，该文提出了一种基于秘密共享技术的取证方案。所提方案在提高取证效率的同时利用数字签名技术验证了所收集数据的真实性与完整性，有效地保障了电子证据的法律效力。%Forensic investigation conflicts with privacy protection. It is important how to collect the evidence admitted in a court while preserving the privacy of irrelevant users. To tackle this problem, Hou et al presented several encryption-based schemes. The main shortcoming of these schemes consists in that both the encryption and decryption procedures are time consuming, espe?cially on huge volume of data. This leads to low efficiency during forensic investigation. In this paper, we propose a secret shar?ing based solution to improve the investigation efficiency. Further, we utilize digital signature to verify data integrity and data au?thenticity so as to ensure that the collected data can be admitted as evidence in a court.
Madsen, P.; Goss, K.
1982-07-01
A social experiment in Denmark is described in which 25 families combine private ownership (each family owns its own home) and collectivism (each family owns 1/25 of the grounds, large common house and other facilities). The superinsulated individual homes are small (< 1000 ft/sup 2/) but the common house (7800 ft/sup 2/) provides dining and meeting facilities for all 25 families as well as a central heating plant. Heat may be supplied from solar, wind and/or oil-fired boiler. Adequate hot water storage is provided using solar collectors and a 55 kW Vesta wind generator (surplus power is sold). All south facing roof surfaces are fitted with solar collectors (4455 ft/sup 2/ total). A total of 70% of the energy used is produced on site (solar and wind). The manner of living and sharing (child care, automobiles, cooking, etc.) is described as well as typical floor plans for the units. Other collective housing in Denmark is described and it is postulated that overdrevet may serve as a model. (MJJ)
Exploring rationality in schizophrenia
Revsbech, Rasmus; Mortensen, Erik Lykke; Owen, Gareth
2015-01-01
Background Empirical studies of rationality (syllogisms) in patients with schizophrenia have obtained different results. One study found that patients reason more logically if the syllogism is presented through an unusual content. Aims To explore syllogism-based rationality in schizophrenia. Method...... Thirty-eight first-admitted patients with schizophrenia and 38 healthy controls solved 29 syllogisms that varied in presentation content (ordinary v. unusual) and validity (valid v. invalid). Statistical tests were made of unadjusted and adjusted group differences in models adjusting for intelligence...... differences became non-significant. Conclusions When taking intelligence and neuropsychological performance into account, patients with schizophrenia and controls perform similarly on syllogism tests of rationality....
Marton, Attila; Constantiou, Ioanna; Thoma, Antonela
De spite the hype the notion of the sharing economy is surrounded by, our understanding of sharing is surprisingly undertheorized. In this paper, we make a first step towards rem edying this state of affairs by analy sing sharing as a s ocial practice. Based on a multi ple - case study, we analyse...... the institutional assemblage of sharing on online platforms to counter the prevalent assumpti o n i n the literature that sharing derives primarily from the shareability of goods and resources. Sharing, we contend, is a fundament al human practice that, in our case study, takes the particular form of coord inated...
Information, Utility & Bounded Rationality
Ortega, Pedro A
2011-01-01
Perfectly rational decision-makers maximize expected utility, but crucially ignore the resource costs incurred when determining optimal actions. Here we employ an axiomatic framework for bounded rational decision-making based on a thermodynamic interpretation of resource costs as information costs. This leads to a variational "free utility" principle akin to thermodynamical free energy that trades off utility and information costs. We show that bounded optimal control solutions can be derived from this variational principle, which leads in general to stochastic policies. Furthermore, we show that risk-sensitive and robust (minimax) control schemes fall out naturally from this framework if the environment is considered as a bounded rational and perfectly rational opponent, respectively. When resource costs are ignored, the maximum expected utility principle is recovered.
Uncertainty, rationality, and agency
Hoek, Wiebe van der
2006-01-01
Goes across 'classical' borderlines of disciplinesUnifies logic, game theory, and epistemics and studies them in an agent-settingCombines classical and novel approaches to uncertainty, rationality, and agency
Crab Rationalization Permit Program
National Oceanic and Atmospheric Administration, Department of Commerce — The Crab Rationalization Program (Program) allocates BSAI crab resources among harvesters, processors, and coastal communities. The North Pacific Fishery Management...
Janusz J. Charatonik
1994-05-01
Full Text Available Spaces which are metrizable completions of the space Q of rationals are described. A characterization of metrizable spaces having the same family of metrizable completions as Q is deduced.
[Concepts of rational taxonomy].
Pavlinov, I Ia
2011-01-01
The problems are discussed related to development of concepts of rational taxonomy and rational classifications (taxonomic systems) in biology. Rational taxonomy is based on the assumption that the key characteristic of rationality is deductive inference of certain partial judgments about reality under study from other judgments taken as more general and a priory true. Respectively, two forms of rationality are discriminated--ontological and epistemological ones. The former implies inference of classifications properties from general (essential) properties of the reality being investigated. The latter implies inference of the partial rules of judgments about classifications from more general (formal) rules. The following principal concepts of ontologically rational biological taxonomy are considered: "crystallographic" approach, inference of the orderliness of organismal diversity from general laws of Nature, inference of the above orderliness from the orderliness of ontogenetic development programs, based on the concept of natural kind and Cassirer's series theory, based on the systemic concept, based on the idea of periodic systems. Various concepts of ontologically rational taxonomy can be generalized by an idea of the causal taxonomy, according to which any biologically sound classification is founded on a contentwise model of biological diversity that includes explicit indication of general causes responsible for that diversity. It is asserted that each category of general causation and respective background model may serve as a basis for a particular ontologically rational taxonomy as a distinctive research program. Concepts of epistemologically rational taxonomy and classifications (taxonomic systems) can be interpreted in terms of application of certain epistemological criteria of substantiation of scientific status of taxonomy in general and of taxonomic systems in particular. These concepts include: consideration of taxonomy consistency from the
Controllability under rational expectations.
Hughes Hallett Andrew; Di Bartolomeo Giovanni; Acocella Nicola
2008-01-01
We show that rational expectations do not affect the controllability of an economic system, either in its static or in its dynamic version, even though their introduction in many other circumstances may make it impossible for the policymaker to affect certain variables due to policy invariance, policy neutrality or time inconsistency problems. The controllability conditions stated by Tinbergen and subsequent authors continue to hold under rational expectations; and when they are satisfied rat...
Phronesis – hermeneutic rationality
Michał Januszkiewicz
2016-01-01
The paper is an attempt to rethink the problem of rationality in the humanities in the context of hermeneutics. The author argues that this concept of rationality must be founded on the Aristotelian concept of practical reason (phronesis). Phronesis is a need for discernment of the self or rather to find itself in its own, tangible, specific situation. This understanding concerns Being-inthe-world and belongs to what in Martin Heidegger’s ontohermeneutics we can determine precisely as underst...
Marton, Attila; Constantiou, Ioanna; Thoma, Antonela
De spite the hype the notion of the sharing economy is surrounded by, our understanding of sharing is surprisingly undertheorized. In this paper, we make a first step towards rem edying this state of affairs by analy sing sharing as a s ocial practice. Based on a multi ple - case study, we analyse...
IMPACT OF ERROR FILTERS ON SHARES IN HALFTONE VISUAL CRYPTOGRAPHY
Sunil Agrawal; Anshul Sharma
2012-01-01
Visual cryptography encodes a secret binary image (SI) into shares of random binary patterns. If the shares are xeroxed onto transparencies, the secret image can be visually decoded by superimposing a qualified subset of transparencies, but no secret information can be obtained from the superposition of a forbidden subset. The binary patterns of the shares, however, have no visual meaning and hinder the objectives of visual cryptography. Halftone visual cryptography encodes a s...
This magazine offers an insight into the growing commercial innovation, civic movements, and political narratives surrounding sharing economy services, solutions and organisational types. It presents a cross-section of the manifold sharing economy services and solutions that can be found in Denmark....... Solutions of sharing that seeks to improve our cities and local communities in both urban and rural environments. 24 sharing economy organisations and businesses addressing urban and rural issues are being portrayed and seven Danish municipalities that have explored the potentials of sharing economy....... Moreover, 15 thought leading experts - professionals and academic - have been invited to give their perspective on sharing economy for cities. This magazine touches upon aspects of the sharing economy as mobility, communities, sustainability, business development, mobility, and urban-rural relation....
Design and Implementation of Hierarchical Visual Cryptography with Expansionless Shares
Pallavi Vijay Chavan
2014-04-01
Full Text Available Visual cryptography is the art of encrypting visual information such as handwritten text, images etc. The encryption takes place in such a way that no mathematical computations are required in order to decrypt the secret. The original information to be encrypted is called as secret. After encryption, ciphers are generated and referred as shares. The part of secret in scrambled form is known as share. Fundamental idea behind visual cryptography is to share the secret among group of nparticipants. In order to share the secret, it is divided inton number of pieces called shares. These shares are distributed among the participants. To reveal the original secret, each participant provides his own share. Complete knowledge of n-1 shares is unable to decrypt the secret. Many visual cryptographic schemes exist. The basic scheme is 2 out of 2 visual cryptography in which the secret is partitioned into exactly two parts. To reveal the secret these two shares must participate. Following figure indicates simple example of 2 out of 2 visual cryptography scheme.
[Rational use of antibiotics].
Walger, P
2016-06-01
International and national campaigns draw attention worldwide to the rational use of the available antibiotics. This has been stimulated by the high prevalence rates of drug-resistant pathogens, such as methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE), a threatening spread of development of resistance in Gram-negative rod-shaped bacteria and the selection of Clostridium difficile with a simultaneous clear reduction in the development of new antibiotics. The implementation of antibiotic stewardship programs aims to maintain their effectiveness by a rational use of the available antibiotics. The essential target of therapy with antibiotics is successful treatment of individual patients with bacterial infections. The optimal clinical treatment results can only be achieved when the toxicity, selection of pathogens and development of resistance are minimized. This article presents the principles of a rational antibiotic therapy.
Davis, Yvette
2011-01-01
Become a Google guru with these effective tips, tricks, and techniques Sure, you use Google. But do you really use Google-and everything it has to offer-in the most effective way possible? Wish you could just sit down with a Google expert who would show you how to take your Google savviness to the next level? With Google Secrets, you can! Tech expert Jerri Ledford reveals the ins, outs, and little-known facts about Google to show you how to sharpen your skills so you can get more done, more efficiently. You may already be familiar with Google's most popular applications, but this indispensable
Algebraic Topology, Rational Homotopy
1988-01-01
This proceedings volume centers on new developments in rational homotopy and on their influence on algebra and algebraic topology. Most of the papers are original research papers dealing with rational homotopy and tame homotopy, cyclic homology, Moore conjectures on the exponents of the homotopy groups of a finite CW-c-complex and homology of loop spaces. Of particular interest for specialists are papers on construction of the minimal model in tame theory and computation of the Lusternik-Schnirelmann category by means articles on Moore conjectures, on tame homotopy and on the properties of Poincaré series of loop spaces.
Phronesis – hermeneutic rationality
Michał Januszkiewicz
2016-06-01
Full Text Available The paper is an attempt to rethink the problem of rationality in the humanities in the context of hermeneutics. The author argues that this concept of rationality must be founded on the Aristotelian concept of practical reason (phronesis. Phronesis is a need for discernment of the self or rather to find itself in its own, tangible, specific situation. This understanding concerns Being-inthe-world and belongs to what in Martin Heidegger’s ontohermeneutics we can determine precisely as understanding in the hermeneutic sense.
Kubilius, Jonas
2014-01-01
Sharing code is becoming increasingly important in the wake of Open Science. In this review I describe and compare two popular code-sharing utilities, GitHub and Open Science Framework (OSF). GitHub is a mature, industry-standard tool but lacks focus towards researchers. In comparison, OSF offers a one-stop solution for researchers but a lot of functionality is still under development. I conclude by listing alternative lesser-known tools for code and materials sharing.
Shift visual cryptography scheme of two secret images
无
2003-01-01
A new visual cryptography scheme of two secret images, which is named the shift visual cryptography of two secret images, is given. The compound function family of a general construction model is also introduced. The uniqueness and validity of this model are proved, and the minimum rows and columns for realizing the scheme are obtained. Compared with visual cryptography of one secret image, the shift visual cryptography scheme can share two secret images with the same size of pixels expansion without losing the contrast. It has randomness and various forms, and furthermore, we can also visually recover two secret images even if the two shares are different in form and color.
Ideal Theory, Real Rationality
Flyvbjerg, Bent
Understanding rationality and power are key to understanding actual political and administrative behavior. Political and administrative theory that ignores this fact stand in danger of being at best irrelevant or, at worst part of the problem it whishes to solve. The paper presents Jürgen Haberma...
In Between Magic and Rationality, Vibeke Steffen, Steffen Jöhncke, and Kirsten Marie Raahauge bring together a diverse range of ethnographies that examine and explore the forms of reflection, action, and interaction that govern the ways different contemporary societies create and challenge...
Dryden, Windy
2010-01-01
In this title, highly respected author, Windy Dryden, discusses some of the ideas that are central to the theory underpinning rational emotive behaviour therapy (REBT). Founded in 1955 by Albert Ellis (1913-2007) and developed in the intervening years, REBT was the first approach to be created within what is now known as the cognitive behaviour therapy (CBT) tradition.
Diagnosis, Dogmatism, and Rationality.
Rabinowitz, Jonathan; Efron, Noah J.
1997-01-01
Presents findings suggesting that misdiagnoses frequently stem from flaws in human information processing, particularly in collecting and using information. Claims that improved diagnostic tools will not remedy the problem. Drawing on the work of Karl Popper and Robin Collingwood, proposes operational principles to ensure a rational diagnostic…
Ideal Theory, Real Rationality
Flyvbjerg, Bent
Understanding rationality and power are key to understanding actual political and administrative behavior. Political and administrative theory that ignores this fact stand in danger of being at best irrelevant or, at worst part of the problem it whishes to solve. The paper presents Jürgen Habermas...
van Eijk, N.
2011-01-01
‘File sharing’ has become generally accepted on the Internet. Users share files for downloading music, films, games, software etc. In this note, we have a closer look at the definition of file sharing, the legal and policy-based context as well as enforcement issues. The economic and cultural impact
Ulhøi, John Parm; Müller, Sabine
2012-01-01
The aim of this paper is twofold. First, this paper comprehensively will review the conceptual and empirical literature to identify such critical underlying mechanisms which enable shared or collective leadership. Second, this article identifies the antecedents and outcomes of shared leadership...... according to the literature review to develop a re-conceptualised and synthesized framework for managing the organizational issues associated with shared leadership on various organizational levels. The paper rectifies this by identifying the critical factors and mechanisms which enable shared leadership...... and its antecedents and outcomes, and to develop a re-conceptualized and synthesized framework of shared leadership. The paper closes with a brief discussion of avenues for future research and implications for managers....
Ulhøi, John Parm; Müller, Sabine
2012-01-01
The aim of this paper is twofold. First, this paper comprehensively will review the conceptual and empirical literature to identify such critical underlying mechanisms which enable shared or collective leadership. Second, this article identifies the antecedents and outcomes of shared leadership...... according to the literature review to develop a re-conceptualised and synthesized framework for managing the organizational issues associated with shared leadership on various organizational levels. The paper rectifies this by identifying the critical factors and mechanisms which enable shared leadership...... and its antecedents and outcomes, and to develop a re-conceptualized and synthesized framework of shared leadership. The paper closes with a brief discussion of avenues for future research and implications for managers....
Rationality and social behavior.
Tullberg, Jan
2003-10-21
This article penetrates the relationship between social behavior and rationality. A critical analysis is made of efforts to classify some behaviors as altruistic, as they simultaneously meet criteria of rationality by not truly being self-destructive. Newcomb's paradox is one attempt to create a hybrid behavior that is both irrational and still meets some criterion of rationality. Such dubious rationality is often seen as a source of altruistic behavior. Group selection is a controversial topic. Sober and Wilson (Unto Others--The Evolution and Psychology of Unselfish Behavior, Harvard University Press, Cambridge, MA, 1998) suggest that a very wide concept of group selection might be used to explain altruism. This concept also includes kin selection and reciprocity, which blurs its focus. The latter mechanisms hardly need further arguments to prove their existence. This article suggests that it is group selection in a strict sense that should be investigated to limit semantic neologism and confusion. In evaluation, the effort to muster a mechanism for altruism out of group selection has not been successful. However, this is not the end to group selection, but rather a good reason to investigate more promising possibilities. There is little reason to burden group selection with the instability of altruism caused by altruistic members of a group having lower fitness than egoistic members. Group selection is much more likely to develop in combination with group egoism. A common project is supported by incitement against free riding, where conformist members joined in solidarity achieve a higher fitness than members pursuing more individualistic options. Group egoism is in no conflict with rationality, and the effects of group selection will be supported rather than threatened by individual selection. Empirical evidence indicates a high level of traits such as conformism and out-group antagonism in line with group egoism. These traits are also likely candidates for
Shteynberg, Garriy
2015-09-01
Shared attention is extremely common. In stadiums, public squares, and private living rooms, people attend to the world with others. Humans do so across all sensory modalities-sharing the sights, sounds, tastes, smells, and textures of everyday life with one another. The potential for attending with others has grown considerably with the emergence of mass media technologies, which allow for the sharing of attention in the absence of physical co-presence. In the last several years, studies have begun to outline the conditions under which attending together is consequential for human memory, motivation, judgment, emotion, and behavior. Here, I advance a psychological theory of shared attention, defining its properties as a mental state and outlining its cognitive, affective, and behavioral consequences. I review empirical findings that are uniquely predicted by shared-attention theory and discuss the possibility of integrating shared-attention, social-facilitation, and social-loafing perspectives. Finally, I reflect on what shared-attention theory implies for living in the digital world.
Orgad, Yariv
2014-08-01
In this paper I present a novel interpretation of family secrets. Leaning on Bion's concept of -K, the constitution of secrecy is interpreted in terms of family dynamics that actively prevent knowledge formation and mental growth. Family secrets are interpreted as a destructive process that attacks the family's truth-generating-space - the shared semiotic space within which meanings are constituted through family relationships. The paper explores the microstructure interpersonal process of -K through the analysis of Mike Leigh's movie, Secrets and Lies. Two scenes in the movie are used to demonstrate how -K is worked out in the form of a specific intersubjective semiotic endeavor that unconsciously blocks the process of meaning-making.
IMPACT OF ERROR FILTERS ON SHARES IN HALFTONE VISUAL CRYPTOGRAPHY
Sunil Agrawal
2012-05-01
Full Text Available Visual cryptography encodes a secret binary image (SI into shares of random binary patterns. If the shares are xeroxed onto transparencies, the secret image can be visually decoded by superimposing a qualified subset of transparencies, but no secret information can be obtained from the superposition of a forbidden subset. The binary patterns of the shares, however, have no visual meaning and hinder the objectives of visual cryptography. Halftone visual cryptography encodes a secret binary image into n halftone shares (images carrying significant visual information. When secrecy is important factor rather than the quality of recovered image the shares must be of better visual quality. Different filters such as Floyd-Steinberg, Jarvis, Stuki, Burkes, Sierra, and Stevenson’s-Arce are used and their impact on visual quality of shares is seen. The simulation shows that error filters used in error diffusion lays a great impact on the visual quality of the shares.
VT - Vermont Rational Service Areas
Vermont Center for Geographic Information — Data Layer Name: Vermont Rational Service Areas (RSAs)Alternate Name: Vermont RSAsOverview:Rational Service Areas (RSAs), originally developed in 2001 and revised in...
Rational management of epilepsy.
Viswanathan, Venkataraman
2014-09-01
Management of epilepsies in children has improved considerably over the last decade, all over the world due to the advances seen in the understanding of the patho-physiology of epileptogenesis, availability of both structural and functional imaging studies along with better quality EEG/video-EEG recordings and the availability of a plethora of newer anti-epileptic drugs which are tailormade to act on specific pathways. In spite of this, there is still a long way to go before one is able to be absolutely rational about which drug to use for which type of epilepsy. There have been a lot of advances in the area of epilepsy surgery and is certainly gaining ground for specific cases. Better understanding of the genetic basis of epilepsies will hopefully lead to a more rational treatment plan in the future. Also, a lot of work needs to be done to dispel various misunderstandings and myths about epilepsy which still exists in our country.
Holdt Christensen, Peter
The concept of knowledge management has, indeed, become a buzzword that every single organization is expected to practice and live by. Knowledge management is about managing the organization's knowledge for the common good of the organization -but practicing knowledge management is not as simple...... as that. This article focuses on knowledge sharing as the process seeking to reduce the resources spent on reinventing the wheel.The article introduces the concept of time sensitiveness; i.e. that knowledge is either urgently needed, or not that urgently needed. Furthermore, knowledge sharing...... is considered as either a push or pull system. Four strategies for sharing knowledge - help, post-it, manuals and meeting, and advice are introduced. Each strategy requires different channels for sharing knowledge. An empirical analysis in a production facility highlights how the strategies can be practiced....
Alternative Disaster Feeding Ration
2012-06-08
is that a healthy person can last about a week without food, but children are more vulnerable lasting for just a few days. In these scenarios, the...ration bar could be edible across different health or dietary constrained populations. For example, diabetics or those with high cholesterol could...Hurricane Katrina was a powerful Category 5 storm that devastated the southeastern states along the Gulf of Mexico in 2005.2 Having seen the aftermath
Realization theory for rational systems
Ně mcová, J.; Schuppen, J.H. van
2008-01-01
In this paper we solve the problem of realization of response maps for rational systems. Sufficient and necessary conditions for a response map to be realizable by a rational system are presented. The properties of rational realizations such as observability, controllability, and minimality are stud
Computational Intelligence Determines Effective Rationality
无
2008-01-01
Rationality is a fundamental concept in economics. Most researchers will accept that human beings are not fully rational.Herbert Simon suggested that we are "bounded rational". However, it is very difficult to quantify "bounded rationality", and therefore it is difficult to pinpoint its impact to all those economic theories that depend on the assumption of full rationality. Ariel Rubinstein proposed to model bounded rationality by explicitly specifying the decision makers' decision-making procedures. This paper takes a computational point of view to Rubinstein's approach. From a computational point of view, decision procedures can be encoded in algorithms and heuristics. We argue that, everything else being equal, the effective rationality of an agent is determined by its computational power - we refer to this as the computational intelligence determines effective rationality (CIDER) theory. This is not an attempt to propose a unifying definition of bounded rationality. It is merely a proposal of a computational point of view of bounded rationality. This way of interpreting bounded rationality enables us to (computationally) reason about economic systems when the full rationality assumption is relaxed.
Multiparty Quantum Secret Report
DENG Fu-Guo; LI Xi-Han; LI Chun-Yan; ZHOU Ping; LIANG Yu-Jie; ZHOU Hong-Yu
2006-01-01
@@ A multiparty quantum secret report scheme is proposed with quantum encryption. The boss Alice and her M agents first share a sequence of (M + 1)-particle Greenberger-Horne-Zeilinger (GHZ) states that only Alice knows which state each (M + 1)-particle quantum system is in. Each agent exploits a controlled-not (CNot) gate to encrypt the travelling particle by using the particle in the GHZ state as the control qubit. The boss Alice decrypts the travelling particle with a CNot gate after performing a σx operation on her particle in the GHZ state or not.After the GHZ states (the quantum key) are used up, the parties check whether there is a vicious eavesdropper,say Eve, monitoring the quantum line, by picking out some samples from the GHZ states shared and measuring them with two measuring bases. After confirming the security of the quantum key, they use the remaining GHZ states repeatedly for the next round of quantum communication. This scheme has the advantage of high intrinsic efficiency for the qubits and total efficiency.
Melioration as Rational Choice: Sequential Decision Making in Uncertain Environments
Sims, Chris R.; Neth, Hansjorg; Jacobs, Robert A.; Gray, Wayne D.
2013-01-01
Melioration--defined as choosing a lesser, local gain over a greater longer term gain--is a behavioral tendency that people and pigeons share. As such, the empirical occurrence of meliorating behavior has frequently been interpreted as evidence that the mechanisms of human choice violate the norms of economic rationality. In some environments, the…
Mandal, Soma; Moudgil, Mee'nal; Mandal, Sanat K
2009-12-25
In this article, current knowledge of drug design is reviewed and an approach of rational drug design is presented. The process of drug development is challenging, expensive, and time consuming, although this process has been accelerated due to the development of computational tools and methodologies. The current target based drug design approach is incomplete because most of the drugs developed by structure guided approaches have been shown to have serious toxic side effects. Otherwise these drugs would have been an ideal choice for the treatment of diseases. Hence, rational drug design would require a multidisciplinary approach. In this regard, incorporation of gene expression technology and bioinformatics tools would be indispensable in the structure based drug design. Global gene expression data and analysis of such data using bioinformatics tools will have numerous benefits such as efficiency, cost effectiveness, time saving, and will provide strategies for combination therapy in addition to overcoming toxic side effects. As a result of incorporation of gene expression data, partial benefit of the structure based drug design is slowly emerging and rapidly changing the approach of the drug development process. To achieve the full benefit of developing a successful drug, multidisciplinary approaches (approaches such as computational chemistry and gene expression analysis, as discussed in this article) would be necessary. In the future, there is adequate room for the development of more sophisticated methodologies.
Ram Samudrala
2009-04-01
Full Text Available The type III secretion system is an essential component for virulence in many Gram-negative bacteria. Though components of the secretion system apparatus are conserved, its substrates--effector proteins--are not. We have used a novel computational approach to confidently identify new secreted effectors by integrating protein sequence-based features, including evolutionary measures such as the pattern of homologs in a range of other organisms, G+C content, amino acid composition, and the N-terminal 30 residues of the protein sequence. The method was trained on known effectors from the plant pathogen Pseudomonas syringae and validated on a set of effectors from the animal pathogen Salmonella enterica serovar Typhimurium (S. Typhimurium after eliminating effectors with detectable sequence similarity. We show that this approach can predict known secreted effectors with high specificity and sensitivity. Furthermore, by considering a large set of effectors from multiple organisms, we computationally identify a common putative secretion signal in the N-terminal 20 residues of secreted effectors. This signal can be used to discriminate 46 out of 68 total known effectors from both organisms, suggesting that it is a real, shared signal applicable to many type III secreted effectors. We use the method to make novel predictions of secreted effectors in S. Typhimurium, some of which have been experimentally validated. We also apply the method to predict secreted effectors in the genetically intractable human pathogen Chlamydia trachomatis, identifying the majority of known secreted proteins in addition to providing a number of novel predictions. This approach provides a new way to identify secreted effectors in a broad range of pathogenic bacteria for further experimental characterization and provides insight into the nature of the type III secretion signal.
The tools of rational product range support
A.I. Jakovlev
2014-09-01
Full Text Available The aim of the article. The aim of the research is to improve the methodological approaches to support the rational range of products under today's market conditions. The results of the analysis. Planning and optimization of product mix does not lose its relevance under the current economic conditions. One of the most important tasks in planning is to determine the range of rational perspective to the enterprise product lines products. In this connection there is a need to expand the use of methodological approaches to support the range of products. Integrated application of methodological approaches for determining the rationality and balance the range of products increases the validity of economic decision-making in the field of marketing of the company by identifying the correlation between the profitability of product lines and their weight in the total production. Using the margin profit as a criterion for ranking groups of products with the construction of the Pareto chart allows for a more flexible product strategy, which under the current market conditions is a significant competitive advantage for the enterprise. The necessary conditions for the effective implementation of the proposals of the authors are the high level of consistency of the strategic, tactical and operational levels of management at the enterprise, as well as the analysis of the results of marketing research about customer satisfaction of product parameters. The using of Pareto charts and Spearman correlation coefficient provides increased sales volumes, increasing the target market share of the enterprise, improving the company's image, reducing the risk of marketing activities, increase the company's profit. The results of this study give the company an opportunity to identify deficiencies in a timely manner in the activities and to identify the main directions of improvement of management systems and production planning. Prospects of this study are to develop the
Credit rationing and firm size
G. CALCAGNINI
2013-10-01
Full Text Available This paper examines the likelihood of credit rationing faced by firms of different size. Contrary to common thought, several recent contributions on this topic argue that, when rationing credit, size alone is not a sufficient condition for discriminating between firms. We show that this result can be predicted using a framework based on the Stiglitz-Weiss model. In particular, in an environment of asymmetric information, we highlight how the likelihood of credit rationing depends upon the shape of the distribution function of project returns, especially its asymmetry and Kurtosis. Our empirical results do not support the hypothesis that small firms face more credit rationing than larger firms.
Hegel's phenomenology of rationality
Huggler, Jørgen
2009-01-01
The aim of this chapter is to elucidate Hegel's conception of rationality in the Phänomenologie des Geistes (1807), and to defend the thesis that he is an author engaged in discussion with a wide variety of sources. He uses sceptical reasoning to form a line of argument with a necessary progression......, although the various materials that he considers are not linked in a simple, compelling logical way. The paper discusses what Hegel aimed at and the methods he used to reach his goal (sect. 1). These considerations are then used to cast an eye on the development of the contents of the book (sect. 2). Last......, the paper presents a metaphysical interpretation of the course of experiences and discusses why Hegel's sceptical method is adequate to the metaphysics of spirit with which the book concludes (sect. 3)....
Liberal rationalism and medical decision-making.
Savulescu, Julian
1997-04-01
I contrast Robert Veatch's recent liberal vision of medical decision-making with a more rationalist liberal model. According to Veatch, physicians are biased in their determination of what is in their patient's overall interests in favour of their medical interests. Because of the extent of this bias, we should abandon the practice of physicians offering what they guess to be the best treatment option. Patients should buddy up with physicians who share the same values -- 'deep value pairing'. The goal of choice is maximal promotion of patient values. I argue that if subjectivism about value and valuing is true, this move is plausible. However, if objectivism about value is true -- that there really are states which are good for people regardless of whether they desire to be in them -- then we should accept a more rationalist liberal alternative. According to this alternative, what is required to decide which course is best is rational dialogue between physicians and patients, both about the patient's circumstances and her values, and not the seeking out of people, physicians or others, who share the same values. Rational discussion requires that physicians be reasonable and empathic. I describe one possible account of a reasonable physician.
Serial interpolation for secure membership testing and matching in a secret-split archive
Kroeger, Thomas M.; Benson, Thomas R.
2016-12-06
The various technologies presented herein relate to analyzing a plurality of shares stored at a plurality of repositories to determine whether a secret from which the shares were formed matches a term in a query. A threshold number of shares are formed with a generating polynomial operating on the secret. A process of serially interpolating the threshold number of shares can be conducted whereby a contribution of a first share is determined, a contribution of a second share is determined while seeded with the contribution of the first share, etc. A value of a final share in the threshold number of shares can be determined and compared with the search term. In the event of the value of the final share and the search term matching, the search term matches the secret in the file from which the shares are formed.
Rational formality of mapping spaces
Felix, Yves
2010-01-01
Let X and Y be finite nilpotent CW complexes with dimension of X less than the connectivity of Y. Generalizing results of Vigu\\'e-Poirrier and Yamaguchi, we prove that the mapping space Map(X,Y) is rationally formal if and only if Y has the rational homotopy type of a finite product of odd dimensional spheres.
Rationality problem for algebraic tori
Hoshi, Akinari
2017-01-01
The authors give the complete stably rational classification of algebraic tori of dimensions 4 and 5 over a field k. In particular, the stably rational classification of norm one tori whose Chevalley modules are of rank 4 and 5 is given. The authors show that there exist exactly 487 (resp. 7, resp. 216) stably rational (resp. not stably but retract rational, resp. not retract rational) algebraic tori of dimension 4, and there exist exactly 3051 (resp. 25, resp. 3003) stably rational (resp. not stably but retract rational, resp. not retract rational) algebraic tori of dimension 5. The authors make a procedure to compute a flabby resolution of a G-lattice effectively by using the computer algebra system GAP. Some algorithms may determine whether the flabby class of a G-lattice is invertible (resp. zero) or not. Using the algorithms, the suthors determine all the flabby and coflabby G-lattices of rank up to 6 and verify that they are stably permutation. The authors also show that the Krull-Schmidt theorem for G-...
Quantum contextuality for rational vectors
Cabello, Adan
2010-01-01
The Kochen-Specker theorem states that noncontextual hidden variable models are inconsistent with the quantum predictions for every yes-no question on a qutrit, corresponding to every projector in three dimensions. It has been suggested [D. A. Meyer, Phys. Rev. Lett. 83, 3751 (1999)] that the inconsistency would disappear when we are restricted to projectors on unit vectors with rational components; that noncontextual hidden variables could reproduce the quantum predictions for rational vectors. Here we show that a qutrit state with rational components violates an inequality valid for noncontextual hidden-variable models [A. A. Klyachko et al., Phys. Rev. Lett. 101, 020403 (2008)] using rational projectors. This shows that the inconsistency remains even when using only rational vectors.
Quantum contextuality for rational vectors
Cabello, Adan, E-mail: adan@us.e [Departamento de Fisica Aplicada II, Universidad de Sevilla, E-41012 Sevilla (Spain); Larsson, Jan-Ake, E-mail: jan-ake.larsson@liu.s [Institutionen foer Systemteknik, Linkoepings Universitet, SE-581 83 Linkoeping (Sweden)
2010-12-01
The Kochen-Specker theorem states that noncontextual hidden variable models are inconsistent with the quantum predictions for every yes-no question on a qutrit, corresponding to every projector in three dimensions. It has been suggested [D.A. Meyer, Phys. Rev. Lett. 83 (1999) 3751] that the inconsistency would disappear when restricting to projectors on unit vectors with rational components; that noncontextual hidden variables could reproduce the quantum predictions for rational vectors. Here we show that a qutrit state with rational components violates an inequality valid for noncontextual hidden-variable models [A.A. Klyachko et al., Phys. Rev. Lett. 101 (2008) 020403] using rational projectors. This shows that the inconsistency remains even when using only rational vectors.
Limited rationality and strategic interaction
Fehr, Ernst; Tyran, Jean-Robert
2008-01-01
Much evidence suggests that people are heterogeneous with regard to their abilities to make rational, forward-looking decisions. This raises the question as to when the rational types are decisive for aggregate outcomes and when the boundedly rational types shape aggregate results. We examine...... this question in the context of a long-standing and important economic problem: the adjustment of nominal prices after an anticipated monetary shock. Our experiments suggest that two types of bounded rationality-money illusion and anchoring-are important behavioral forces behind nominal inertia. However......, depending on the strategic environment, bounded rationality has vastly different effects on aggregate price adjustment. If agents' actions are strategic substitutes, adjustment to the new equilibrium is extremely quick, whereas under strategic complementarity, adjustment is both very slow and associated...
Standby gasoline rationing plan: narrative
1979-02-01
The objectives of the rationing plan are to provide a mechanism capable of maintaining an orderly and equitable market for gasoline in a severe supply shortfall, and capable of rapid implementation; and to comply with requirements of EPCA, which mandates the development of a contingency rationing plan. Eligibility for ration allotments will be based principally on motor vehicle registration records, maintained in a national vehicle registration file. Supplemental allotments will be granted for certain priority activities to ensure the maintenance of essential public services. Supplemental allotments will also be granted to businesses and government organizations with significant off-highway gasoline requirements. Local rationing boards or other offices will be established by states, to provide special allotments to hardship applicants, within DOE guidelines. The background and history of the plan are described. The gasoline rationing plan operations, government operations, program costs, staffing, and funding are also detailed in this report. (MCW)
Implicitization of rational maps
Botbol, Nicolas
2011-01-01
Motivated by the interest in computing explicit formulas for resultants and discriminants initiated by B\\'ezout, Cayley and Sylvester in the eighteenth and nineteenth centuries, and emphasized in the latest years due to the increase of computing power, we focus on the implicitization of hypersurfaces in several contexts. Our approach is based on the use of linear syzygies by means of approximation complexes, following [Bus\\'e Jouanolou 03], where they develop the theory for a rational map $f:P^{n-1}\\dashrightarrow P^n$. Approximation complexes were first introduced by Herzog, Simis and Vasconcelos in [Herzog Simis Vasconcelos 82] almost 30 years ago. The main obstruction for this approximation complex-based method comes from the bad behavior of the base locus of $f$. Thus, it is natural to try different compatifications of $A^{n-1}$, that are better suited to the map $f$, in order to avoid unwanted base points. With this purpose, in this thesis we study toric compactifications $T$ for $A^{n-1}$. We provide re...
Rationality in a general model of choice
Somdeb Lahiri
2015-09-01
Full Text Available In this paper we consider choice correspondences which may be empty-valued. We study conditions under which such choice correspondences are rational, transitively rational, partially rational, partially almost transitive rational, partially almost quasi-transitive rational. This provides fresh impetus and understanding of multi-criteria decision making.
Rational offset approximation of rational Bézier curves
CHENG Min; WANG Guo-jin
2006-01-01
The problem of parametric speed approximation of a rational curve is raised in this paper. Offset curves are widely used in various applications. As for the reason that in most cases the offset curves do not preserve the same polynomial or rational polynomial representations, it arouses difficulty in applications. Thus approximation methods have been introduced to solve this problem. In this paper, it has been pointed out that the crux of offset curve approximation lies in the approximation of parametric speed. Based on the Jacobi polynomial approximation theory with endpoints interpolation, an algebraic rational approximation algorithm of offset curve, which preserves the direction of normal, is presented.
Multi secret image color visual cryptography schemes for general access structures
无
2006-01-01
In the proposed visual cryptography schemes for general access structures, the single secret image black-and-white visual cryptography schemes with meaningful shares have been constructed, in which the shares are innocent looking images. The meaningful shares have not been realized in single secret image color schemes; neither have the multi secret images color schemes. In this paper, the multi secret images color visual cryptography schemes for general access structures with meaningful shares are constructed by the method of matrix concatenation, the pixel expansion is obtained, and the validity of the scheme is proven. In our scheme, the different combination of meaningful color shares can be used to recover distinct color secret images. The multi secret images black-and-white visual cryptography scheme is a special case of our color scheme.
Brothers, Kyle B
2011-04-01
Provider claims to conscientious objection have generated a great deal of heated debate in recent years. However, the conflicts that arise when providers make claims to the "conscience" are only a subset of the more fundamental challenges that arise in health care practice when patients and providers come into conflict. In this piece, the author provides an account of patient-provider conflict from within the moral tradition of St. Thomas Aquinas. He argues that the practice of health care providers should be understood as a form of practical reasoning and that this practical reasoning must necessarily incorporate both "moral" and "professional" commitments. In order to understand how the practical reasoning of provider should account for the needs and commitments of the patient and vice versa, he explores the account of dependence provided by Alasdair MacIntyre in his book Dependent Rational Animals. MacIntyre argues that St. Thomas' account of practical reasoning should be extended and adapted to account for the embodied vulnerability of all humans. In light of this insight, providers must view patients not only as the subjects of their moral reflection but also as fellow humans upon whom the provider depends for feedback on the effectiveness and relevance of her practical reasoning. The author argues that this account precludes responsive providers from adopting either moral or professional conclusions on the appropriateness of interventions outside the individual circumstances that arise in particular situations. The adoption of this orientation toward patients will neither eradicate provider-patient conflict nor compel providers to perform interventions to which they object. But this account does require that providers attend meaningfully to the suffering of patients and seek feedback on whether their intervention has effectively addressed that suffering.
Shared decision making, paternalism and patient choice.
Sandman, Lars; Munthe, Christian
2010-03-01
In patient centred care, shared decision making is a central feature and widely referred to as a norm for patient centred medical consultation. However, it is far from clear how to distinguish SDM from standard models and ideals for medical decision making, such as paternalism and patient choice, and e.g., whether paternalism and patient choice can involve a greater degree of the sort of sharing involved in SDM and still retain their essential features. In the article, different versions of SDM are explored, versions compatible with paternalism and patient choice as well as versions that go beyond these traditional decision making models. Whenever SDM is discussed or introduced it is of importance to be clear over which of these different versions are being pursued, since they connect to basic values and ideals of health care in different ways. It is further argued that we have reason to pursue versions of SDM involving, what is called, a high level dynamics in medical decision-making. This leaves four alternative models to choose between depending on how we balance between the values of patient best interest, patient autonomy, and an effective decision in terms of patient compliance or adherence: Shared Rational Deliberative Patient Choice, Shared Rational Deliberative Paternalism, Shared Rational Deliberative Joint Decision, and Professionally Driven Best Interest Compromise. In relation to these models it is argued that we ideally should use the Shared Rational Deliberative Joint Decision model. However, when the patient and professional fail to reach consensus we will have reason to pursue the Professionally Driven Best Interest Compromise model since this will best harmonise between the different values at stake: patient best interest, patient autonomy, patient adherence and a continued care relationship.
Sharing values, sharing a vision
1993-12-31
Teamwork, partnership and shared values emerged as recurring themes at the Third Technology Transfer/Communications Conference. The program drew about 100 participants who sat through a packed two days to find ways for their laboratories and facilities to better help American business and the economy. Co-hosts were the Lawrence Livermore National Laboratory and the Lawrence Berkeley Laboratory, where most meetings took place. The conference followed traditions established at the First Technology Transfer/Communications Conference, conceived of and hosted by the Pacific Northwest Laboratory in May 1992 in Richmond, Washington, and the second conference, hosted by the National Renewable Energy Laboratory in January 1993 in Golden, Colorado. As at the other conferences, participants at the third session represented the fields of technology transfer, public affairs and communications. They came from Department of Energy headquarters and DOE offices, laboratories and production facilities. Continued in this report are keynote address; panel discussion; workshops; and presentations in technology transfer.
Wæhrens, Anne
2011-01-01
This paper analyses how the memory of the Holocaust has been addressed in the European Parliament from 1989 to 2009. I identify two major changes that occurred in the 1990s and after the 2004 enlargement of the European Union respectively. In the 1990s the war in Bosnia and the question of restit......This paper analyses how the memory of the Holocaust has been addressed in the European Parliament from 1989 to 2009. I identify two major changes that occurred in the 1990s and after the 2004 enlargement of the European Union respectively. In the 1990s the war in Bosnia and the question...... of restitution universalised the memory of the Holocaust and made it present. The 2004 enlargement brought the memory of Soviet Communism into the Union and made it a central task to construct a community of memory that includes both the memory of the Holocaust and of Soviet Communism. The analysis also...... identifies what seems to be a political memory split between Left and Right; and it shows that the time might not be ripe for a shared European memory....
Collective action and rationality models
Luis Miguel Miller Moya
2004-01-01
Full Text Available The Olsonian theory of collective action (Olson, 1965 assumes a model of economic rationality, based on a simple calculus between costs and benefits, that can be hardly hold at present, given the models of rationality proposed recently by several fields of research. In relation to these fields, I will concentrate in two specific proposals, namely: evolutionary game theory and, over all, the theory of bounded rationality. Both alternatives are specially fruitful in order to propose models that do not need a maximizing rationality, or environments of complete and perfect information. Their approaches, based on the possibility of individual learning over the time, have contributed to the analysis of the emergence of social norms, which is something really necessary to the resolution of problems related to cooperation. Thus, this article asserts that these two new theoretical contributions make feasible a fundamental advance in the study of collective action.
Rationality in the Cryptographic Model
Hubacek, Pavel
This thesis presents results in the field of rational cryptography. In the first part we study the use of cryptographic protocols to avoid mediation and binding commitment when implementing game theoretic equilibrium concepts. First, we concentrate on the limits of cryptographic cheap talk....... The second part presents a study of the problem of verifiable delegation of computation in the rational setting. We define rational arguments, an extension of the recent concept of rational proofs into the computational setting, and give a single round delegation scheme for the class NC1, of search problems...... computable by log-space uniform circuits of logarithmic depth, with a sub-linear time verifier. While our approach provides a weaker (yet arguably meaningful) guarantee of soundness, it compares favorably with each of the known delegation schemes in at least one aspect. Our protocols are simple, rely...
Monodromy Substitutions and Rational Blowdowns
Endo, Hisaaki; van Horn-Morris, Jeremy
2010-01-01
We introduce several new families of relations in the mapping class groups of planar surfaces, each equating two products of right-handed Dehn twists. The interest of these relations lies in their geometric interpretation in terms of rational blowdowns of 4-manifolds, specifically via monodromy substitution in Lefschetz fibrations. The simplest example is the lantern relation, already shown by the first author and Gurtas to correspond to rational blowdown along a -4 sphere; here we give relations that extend that result to realize the "generalized" rational blowdowns of Fintushel-Stern and Park by monodromy subsitution, as well as several of the families of rational blowdowns discovered by Stipsicz-Szab\\'o-Wahl.
Rational reconstructions of modern physics
Mittelstaedt, Peter
2013-01-01
Newton’s classical physics and its underlying ontology are loaded with several metaphysical hypotheses that cannot be justified by rational reasoning nor by experimental evidence. Furthermore, it is well known that some of these hypotheses are not contained in the great theories of Modern Physics, such as the theory of Special Relativity and Quantum Mechanics. This book shows that, on the basis of Newton’s classical physics and by rational reconstruction, the theory of Special Relativity as well as Quantum Mechanics can be obtained by partly eliminating or attenuating the metaphysical hypotheses. Moreover, it is shown that these reconstructions do not require additional hypotheses or new experimental results. In the second edition the rational reconstructions are completed with respect to General Relativity and Cosmology. In addition, the statistics of quantum objects is elaborated in more detail with respect to the rational reconstruction of quantum mechanics. The new material completes the approach of t...
Constructing rational maps with cluster points using the mating operation
Sharland, Thomas
2011-01-01
In this article, we show that all admissible rational maps with fixed or period two cluster cycles can be constructed by the mating of polynomials. We also investigate the polynomials which make up the matings that construct these rational maps. In the one cluster case, one of the polynomials must be an $n$-rabbit and in the two cluster case, one of the maps must be either $f$, a "double rabbit", or $g$, a secondary map which lies in the wake of the double rabbit $f$. There is also a very simple combinatorial way of classifiying the maps which must partner the aforementioned polynomials to create rational maps with cluster cycles. Finally, we also investigate the multiplicities of the shared matings arising from the matings in the paper.
The rationing agenda in the NHS. Rationing Agenda Group.
New, B
1996-06-22
The Rationing Agenda Group has been founded to deepen the British debate on rationing health care. It believes that rationing in health care is inevitable and that the public must be involved in the debate about issues relating to rationing. The group comprises people from all parts of health care, none of whom represent either their group or their institutions. RAG has begun by producing this document, which attempts to set an agenda of all the issues that need to be considered when debating the rationing of health care. We hope for responses to the document. The next stage will be to incorporate the responses into the agenda. Then RAG will divide the agenda into manageable chunks and commission expert, detailed commentaries. From this material a final paper will be published and used to prompt public debate. This stage should be reached early in 1997. While these papers are being prepared RAG is developing ways to involve the public in the debate and evaluate the whole process. We present as neutrally as possible all the issues related to rationing and priority setting in the NHS. We focus on the NHS for two reasons. Firstly, for those of us resident in the United Kingdom the NHS is the health care system with which we are most familiar and most concerned. Secondly, focusing on one system alone allows more coherent analysis than would be possible if issues in other systems were included as well. Our concern is with the delivery of health care, not its finance, though we discuss the possible effects of changing the financing system of the NHS. Finally, though our position is neutral, we hold two substantive views--namely, that rationing is unavoidable and that there should be more explicit debate about the principles and issues concerned. We consider the issues under four headings: preliminaries, ethics, democracy, and empirical questions. Preliminaries deal with the semantics of rationing, whether rationing is necessary, and with the range of services to which
Is Polish Crime Economically Rational?
2010-01-01
This study investigates whether crime in Poland is governed by economic rationality. An economic model of rational behavior claims that the propensity to commit criminal activi-ties is negatively related to deterrence. The potential presence of higher risk profiles for certain population segments is investigated. Panel data aggregated to sub-regional levels and observed annually for the years 2003 to 2005 are applied. Controls for endogeneity among criminal activity level and deterrence, intr...
Samudrala, Ram; Heffron, Fred; McDermott, Jason E.
2009-04-24
The type III secretion system is an essential component for virulence in many Gram-negative bacteria. Though components of the secretion system apparatus are conserved, its substrates, effector proteins, are not. We have used a machine learning approach to identify new secreted effectors. The method integrates evolutionary measures, such as the pattern of homologs in a range of other organisms, and sequence-based features, such as G+C content, amino acid composition and the N-terminal 30 residues of the protein sequence. The method was trained on known effectors from Salmonella typhimurium and validated on a corresponding set of effectors from Pseudomonas syringae, after eliminating effectors with detectable sequence similarity. The method was able to identify all of the known effectors in P. syringae with a specificity of 84% and sensitivity of 82%. The reciprocal validation, training on P. syringae and validating on S. typhimurium, gave similar results with a specificity of 86% when the sensitivity level was 87%. These results show that type III effectors in disparate organisms share common features. We found that maximal performance is attained by including an N-terminal sequence of only 30 residues, which agrees with previous studies indicating that this region contains the secretion signal. We then used the method to define the most important residues in this putative secretion signal. Finally, we present novel predictions of secreted effectors in S. typhimurium, some of which have been experimentally validated, and apply the method to predict secreted effectors in the genetically intractable human pathogen Chlamydia trachomatis. This approach is a novel and effective way to identify secreted effectors in a broad range of pathogenic bacteria for further experimental characterization and provides insight into the nature of the type III secretion signal.
Interpolation of rational matrix functions
Ball, Joseph A; Rodman, Leiba
1990-01-01
This book aims to present the theory of interpolation for rational matrix functions as a recently matured independent mathematical subject with its own problems, methods and applications. The authors decided to start working on this book during the regional CBMS conference in Lincoln, Nebraska organized by F. Gilfeather and D. Larson. The principal lecturer, J. William Helton, presented ten lectures on operator and systems theory and the interplay between them. The conference was very stimulating and helped us to decide that the time was ripe for a book on interpolation for matrix valued functions (both rational and non-rational). When the work started and the first partial draft of the book was ready it became clear that the topic is vast and that the rational case by itself with its applications is already enough material for an interesting book. In the process of writing the book, methods for the rational case were developed and refined. As a result we are now able to present the rational case as an indepe...
The Rationality Prohibition of Riba (Usury
Sofhian
2015-10-01
Full Text Available Usury (henceforth called as riba in fact has long been known and have been progressing in meaning. The study of riba was not only discussed seriously by Muslims but also other religions. If flashed back to more than two thousand years ago, the study of riba has been discussed by non-Muslims, such as Hindu, Buddhist, Jewish, Greek, Roman and Christian. In Islam, debate about riba and bank interest indicated that the problem of riba very closely related to the issue of muamalah especially those that occur in Banks and Non- Bank financial. Riba evolution concept toward interest cannot be separated from the development of the financial institutions. Therefore, this journal examine and analyze the substance of the issues of interest in a rational perspective, and at the end of this journal offers loss and profit sharing system as an alternative solution to the system of interest in transaction systems of bank and non- bank.
Love and rationality: on some possible rational effects of love
Gustavo Ortiz-Millán
Full Text Available In this paper I defend the idea that rather than disrupting rationality, as the common-sense conception has done it, love may actually help us to develop rational ways of thinking and acting. I make the case for romantic or erotic love, since this is the kind of love that is more frequently associated with irrationality in acting and thinking. I argue that this kind of love may make us develop epistemic and practical forms of rationality. Based on an analysis of its characteristic action tendencies, I argue that love may help us to develop an instrumental form of rationality in determining the best means to achieve the object of love. It may also narrow down the number of practical considerations that may help us to achieve our goals. Finally, love may generate rational ways of belief-formation by framing the parameters taken into account in perception and attention, and by bringing into light only a small portion of the epistemic information available. Love may make us perceive reality more acutely.
Working with resistance in rational emotive behaviour therapy
Dryden, Windy; Neenan, Michael
2011-01-01
Productive therapeutic change is facilitated when the therapist and client have a good therapeutic relationship, share views on salient therapeutic matters, agree on goals to enhance client well-being, and understand what they each have to do to achieve the goals of therapy. In this book Windy Dryden and Michael Neenan address the difficulties that both client and therapist bring to rational emotive behaviour therapy (REBT) when either party is resistant to change.\\ud \\ud Divided into two par...
Experiments With Queries Over Encrypted Data Using Secret Sharing
Brinkman, R.; Schoenmakers, B.; Doumen, J.M.; Jonker, W.; Jonker, W.; Petkovic, M.
2005-01-01
To avoid insider attacks one cannot rely on access control to protect a database scheme. Encrypting the database is a better option. This paper describes a working prototype of an encrypted database system that allows remote querying over the encrypted data. Experiments with the system show the prac
Experiments with Queries over Encrypted Data Using Secret Sharing
Brinkman, R.; Schoenmakers, B.; Doumen, J.; Jonker, W.
2005-01-01
To avoid insider attacks one cannot rely on access control to protect a database scheme. Encrypting the database is a better option. This paper describes a working prototype of an encrypted database system that allows remote querying over the encrypted data. Experiments with the system show the prac
Linear round bit-decomposition of secret-shared values
Veugen, P.J.M.
2015-01-01
In the field of signal processing in the encrypted domain, linear operations are usually easy to perform, whereas multiplications, and bitwise operations like comparison, are more costly in terms of computation and communication. These bitwise operations frequently require a decomposition of the sec
Authentication Without Secrets
Pierson, Lyndon G. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Robertson, Perry J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
2015-11-01
This work examines a new approach to authentication, which is the most fundamental security primitive that underpins all cyber security protections. Current Internet authentication techniques require the protection of one or more secret keys along with the integrity protection of the algorithms/computations designed to prove possession of the secret without actually revealing it. Protecting a secret requires physical barriers or encryption with yet another secret key. The reason to strive for "Authentication without Secret Keys" is that protecting secrets (even small ones only kept in a small corner of a component or device) is much harder than protecting the integrity of information that is not secret. Promising methods are examined for authentication of components, data, programs, network transactions, and/or individuals. The successful development of authentication without secret keys will enable far more tractable system security engineering for high exposure, high consequence systems by eliminating the need for brittle protection mechanisms to protect secret keys (such as are now protected in smart cards, etc.). This paper is a re-release of SAND2009-7032 with new figures numerous edits.
Axioms for Rational Reinforcement Learning
Sunehag, Peter
2011-01-01
We provide a formal, simple and intuitive theory of rational decision making including sequential decisions that affect the environment. The theory has a geometric flavor, which makes the arguments easy to visualize and understand. Our theory is for complete decision makers, which means that they have a complete set of preferences. Our main result shows that a complete rational decision maker implicitly has a probabilistic model of the environment. We have a countable version of this result that brings light on the issue of countable vs finite additivity by showing how it depends on the geometry of the space which we have preferences over. This is achieved through fruitfully connecting rationality with the Hahn-Banach Theorem. The theory presented here can be viewed as a formalization and extension of the betting odds approach to probability of Ramsey and De Finetti.
Rational points on elliptic curves
Silverman, Joseph H
2015-01-01
The theory of elliptic curves involves a pleasing blend of algebra, geometry, analysis, and number theory. This book stresses this interplay as it develops the basic theory, thereby providing an opportunity for advanced undergraduates to appreciate the unity of modern mathematics. At the same time, every effort has been made to use only methods and results commonly included in the undergraduate curriculum. This accessibility, the informal writing style, and a wealth of exercises make Rational Points on Elliptic Curves an ideal introduction for students at all levels who are interested in learning about Diophantine equations and arithmetic geometry. Most concretely, an elliptic curve is the set of zeroes of a cubic polynomial in two variables. If the polynomial has rational coefficients, then one can ask for a description of those zeroes whose coordinates are either integers or rational numbers. It is this number theoretic question that is the main subject of this book. Topics covered include the geometry and ...
Epistemic Immodesty and Embodied Rationality
Giovanni Rolla
Full Text Available ABSTRACT Based on Pritchard's distinction (2012, 2016 between favoring and discriminating epistemic grounds, and on how those grounds bear on the elimination of skeptical possibilities, I present the dream argument as a moderate skeptical possibility that can be reasonably motivated. In order to block the dream argument skeptical conclusion, I present a version of phenomenological disjunctivism based on Noë's actionist account of perceptual consciousness (2012. This suggests that perceptual knowledge is rationally grounded because it is a form of embodied achievement - what I call embodied rationality -, which offers a way of dissolving the pseudo-problem of epistemic immodesty, namely, the seemingly counterintuitive thesis that one can acquire rationally grounded knowledge that one is not in a radical skeptical scenario.
Rational choice in field archaelology
Cătălin Pavel
2011-11-01
Full Text Available In the present article I attempt to apply advances in the study of instrumental and epistemic rationality to field archaeology in order to gain insights into the ways archaeologists reason. The cognitive processes, particularly processes of decision making, that enable archaeologists to conduct the excavation in the trench have not been adequately studied so far. I take my cues from two different bodies of theory. I first inquire into the potential that rational choice theory (RCT may have in modeling archaeological behaviour, and I define subjective expected utility, which archaeologists attempt to maximize, in terms of knowledge acquisition and social gain. Following Elster’s criticism of RCT, I conclude that RCT’s standards for rational action do not correspond with those ostensibly used in field archaeology, but that instrumental rationality has a prominent role in the “archaeological experiment”. I further explore if models proposed as reaction to RCT may account for archaeological decision making. I focus on fast and frugal heuristics, and search for archaeological illustrations for some of the cognitive biases that are better documented in psychological literature. I document confirmation and congruence biases, the endowment effect, observer-expectancy bias, illusory correlation, clustering illusion, sunk cost bias, and anchoring, among others and I propose that some of these biases are used as cognitive tools by archaeologists at work and retain epistemic value. However, I find formal logic to be secondary in the development of archaeological reasoning, with default logic and defeasible logic being used instead. I emphasize scientific knowledge as an actively negotiated social product of human inquiry, and conclude that to describe rationality in field archaeology a bounded rationality model is the most promising avenue of investigation.
Secret Key Generation for a Pairwise Independent Network Model
Nitinawarat, Sirin; Barg, Alexander; Narayan, Prakash; Reznik, Alex
2010-01-01
We consider secret key generation for a "pairwise independent network" model in which every pair of terminals observes correlated sources that are independent of sources observed by all other pairs of terminals. The terminals are then allowed to communicate publicly with all such communication being observed by all the terminals. The objective is to generate a secret key shared by a given subset of terminals at the largest rate possible, with the cooperation of any remaining terminals. Secrecy is required from an eavesdropper that has access to the public interterminal communication. A (single-letter) formula for secret key capacity brings out a natural connection between the problem of secret key generation and a combinatorial problem of maximal packing of Steiner trees in an associated multigraph. An explicit algorithm is proposed for secret key generation based on a maximal packing of Steiner trees in a multigraph; the corresponding maximum rate of Steiner tree packing is thus a lower bound for the secret ...
Rationalizing the Promotion of Non-Rational Behaviors in Organizations.
Smith, Peter A. C.; Sharma, Meenakshi
2002-01-01
Organizations must balance rational/technical efficiency and emotions. Action learning has been proven to be effective for developing emotional openness in the workplace. Facilitators of action learning should draw upon the disciplines of counseling, Gestalt, psychodynamics, and Eastern philosophies. (Contains 23 references.) (SK)
Mental health as rational autonomy.
Edwards, R B
1981-08-01
Rather than eliminate the terms "mental health and illness" because of the grave moral consequences of psychiatric labeling, conservative definitions are proposed and defended. Mental health is rational autonomy, and mental illness is the sustained loss of such. Key terms are explained, advantages are explored, and alternative concepts are criticized. The value and descriptive components of all such definitions are consciously acknowledged. Where rational autonomy is intact, mental hospitals and psychotherapists should not think of themselves as treating an illness. Instead, they are functioning as applied axiologists, moral educators, spiritual mentors, etc. They deal with what Szasz has called "personal, social, and ethical problems in living." But mental illness is real.
Public policy, rationality and reason
Rodolfo Canto Sáenz
2015-07-01
Full Text Available This work suggests the incorporation of practical reason in the design, implementation and evaluation of public policies, alongside instrumental rationality. It takes two proposals that today point in this direction: Rawls distinction between reasonable (practical reason and rational (instrumental reason and what this author calls the CI Procedure (categorical imperative procedure and Habermas model of deliberative democracy. The main conclusion is that the analysis of public policies can not be limited to rather narrow limits of science, but requires the contribution of political and moral philosophy.
Rational Reconstructions of Modern Physics
Mittelstaedt, Peter
2011-01-01
Newton’s classical physics and its underlying ontology are loaded with several metaphysical hypotheses that cannot be justified by rational reasoning nor by experimental evidence. Furthermore, it is well known that some of these hypotheses are not contained in the great theories of modern physics, such as the theory of relativity and quantum mechanics. This book shows that, on the basis of Newton’s classical physics and by rational reconstruction, the theory of relativity as well as quantum mechanics can be obtained by partly eliminating or attenuating the metaphysical hypotheses. Moreover, it is shown that these reconstructions do not require additional hypotheses or new experimental results.
Immunoglobins in mammary secretions
Hurley, W L; Theil, Peter Kappel
2013-01-01
Immunoglobulins secreted in colostrum and milk by the lactating mammal are major factors providing immune protection to the newborn. Immunoglobulins in mammary secretions represent the cumulative immune response of the lactating animal to exposure to antigenic stimulation that occurs through inte...
ASYNCHRONOUS BYZANTINE AGREEMENT PROTOCOL BASED ON VERIFIABLE SIGNATURE SHARING
Ji Dongyao; Feng Dengguo
2006-01-01
An ([n / 3]- 1 )-resilient Asynchronous Byzantine Agreement Protocol (ABAP) that combines verifiable signature sharing and random secret sharing is proposed. The protocol works in the asynchronous network environment and produces Byzantine agreement within a fixed expected number of computational rounds. The correctness of the protocol is proved in theory.
ACTH-Secreting Pheochromocytoma. Case report
N S Kuznetsov
2012-12-01
Full Text Available Ectopic hormone-secreting pheochromocytomas are rare. Only case reports exist in the literature. Despite the large number of guides on diagnosis and treatment of pheochromocytoma, and Cushing syndrome, the extreme rarity of ectopic ACTH-syndrome caused by pheochromocytoma, and complexity of clinical cause numerous diagnostic errors leading to treatment failure. Therefore, we belive it appropriate to share our experience of this group of patients.
Optimal public rationing and price response.
Grassi, Simona; Ma, Ching-To Albert
2011-12-01
We study optimal public health care rationing and private sector price responses. Consumers differ in their wealth and illness severity (defined as treatment cost). Due to a limited budget, some consumers must be rationed. Rationed consumers may purchase from a monopolistic private market. We consider two information regimes. In the first, the public supplier rations consumers according to their wealth information (means testing). In equilibrium, the public supplier must ration both rich and poor consumers. Rationing some poor consumers implements price reduction in the private market. In the second information regime, the public supplier rations consumers according to consumers' wealth and cost information. In equilibrium, consumers are allocated the good if and only if their costs are below a threshold (cost effectiveness). Rationing based on cost results in higher equilibrium consumer surplus than rationing based on wealth.
Teaching Rational Decision-Making.
Woolever, Roberts
1978-01-01
Presented is an outline of a college course, "Education in American Society," that focused on teaching students rational decision-making skills while examining current issues in American Education. The outline is followed by student comments, reactions, and evaluations of the course. (JMD)
On Counting the Rational Numbers
Almada, Carlos
2010-01-01
In this study, we show how to construct a function from the set N of natural numbers that explicitly counts the set Q[superscript +] of all positive rational numbers using a very intuitive approach. The function has the appeal of Cantor's function and it has the advantage that any high school student can understand the main idea at a glance…
Rational Exponentials and Continued Fractions
Denny, J. K.
2012-01-01
Using continued fraction expansions, we can approximate constants, such as pi and e, using an appropriate integer n raised to the power x[superscript 1/x], x a suitable rational. We review continued fractions and give an algorithm for producing these approximations.
Personal Autonomy and Rational Suicide.
Webber, May A.; Shulman, Ernest
That certain suicides (which can be designated as rational) ought not to be interfered with is closely tied to the notion of the "right to autonomy." Specifically it is because the individual in question has this right that interference is prohibited. A proper understanding of the right to autonomy, while essential to understanding why suicide is…
Rational Normalization of Concentration Measures.
Bonckaert, P.; Egghe, L.
1991-01-01
Discusses normalization features of good concentration measures and extends the range of values of concentration measures that are population-size-independent. Rational normalization is described, and mathematical formulas for the coefficient of variation, Pratt's measure, the Gini index, Theil's measure, and Atkinson's indices are explained. (14…
Dynamics of market structure driven by the degree of consumer’s rationality
Yanagita, Tatsuo; Onozaki, Tamotsu
2010-03-01
We study a simple model of market share dynamics with boundedly rational consumers and firms interacting with each other. As the number of consumers is large, we employ a statistical description to represent firms’ distribution of consumer share, which is characterized by a single parameter representing how rationally the mass of consumers pursue higher utility. As the boundedly rational firm does not know the shape of demand function it faces, it revises production and price so as to raise its profit with the aid of a simple reinforcement learning rule. Simulation results show that (1) three phases of market structure, i.e. the uniform share phase, the oligopolistic phase, and the monopolistic phase, appear depending upon how rational consumers are, and (2) in an oligopolistic phase, the market share distribution of firms follows Zipf’s law and the growth-rate distribution of firms follows Gibrat’s law, and (3) an oligopolistic phase is the best state of market in terms of consumers’ utility but brings the minimum profit to the firms because of severe competition based on the moderate rationality of consumers.
Incretin secretion: direct mechanisms
Balk-Møller, Emilie; Holst, Jens Juul; Kuhre, Rune Ehrenreich
2014-01-01
The incretin hormones glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide 1 (GLP-1) are secreted from gastro-intestinal K- and L-cells, respectively, and play an important role in post-prandial blood glucose regulation. They do this by direct stimulation of the pancreatic β...... enzyme responsible for incretin degradation (dipeptidyl peptidase-4) is inhibited (drugs are already on the market) while the secretion of endogenous GLP-1 secretion is stimulated at the same time may prove particularly rewarding. In this section we review current knowledge on the mechanisms for direct...
Love and rationality: on some possible rational effects of love
Gustavo Ortiz-Millán
2007-01-01
Full Text Available In this paper I defend the idea that rather than disrupting rationality, as the common-sense conception has done it, love may actually help us to develop rational ways of thinking and acting. I make the case for romantic or erotic love, since this is the kind of love that is more frequently associated with irrationality in acting and thinking. I argue that this kind of love may make us develop epistemic and practical forms of rationality. Based on an analysis of its characteristic action tendencies, I argue that love may help us to develop an instrumental form of rationality in determining the best means to achieve the object of love. It may also narrow down the number of practical considerations that may help us to achieve our goals. Finally, love may generate rational ways of belief-formation by framing the parameters taken into account in perception and attention, and by bringing into light only a small portion of the epistemic information available. Love may make us perceive reality more acutely.Neste artigo defendo a idéia de que, em vez de perturbar a racionalidade, como a concepção do senso comum o faz, o amor pode, na verdade, ajudar-nos a desenvolver modos racionais de pensar e agir. Dou bons argumentos para o amor romântico ou erótico, uma vez que esse é o tipo de amor que é mais freqüentemente associado à irracionalidade no agir e no pensar. Argumento que esse tipo de amor pode fazer-nos desenvolver formas epistêmicas e práticas de racionalidade. Com base em uma análise de suas tendências características para a ação, argumento que o amor pode ajudar-nos a desenvolver uma forma instrumental de racionalidade para se determinar o melhor meio de atingir o objeto de amor. Ele também pode limitar o número de considerações práticas que podem ajudar-nos a atingir os nossos objetivos. Finalmente, o amor pode gerar modos racionais de formação de crenças ao estruturar os parâmetros considerados na percepção e na aten
WAVELET RATIONAL FILTERS AND REGULARITY ANALYSIS
Zheng Kuang; Ming-gen Cui
2000-01-01
In this paper, we choose the trigonometric rational functions as wavelet filters and use them to derive various wavelets. Especially for a certain family of wavelets generated by the rational filters, the better smoothness results than Daubechies' are obtained.
Rationality, mental causation and social sciences
Mladenović Ivan
2009-01-01
Full Text Available The aim of this paper is to investigate the role of mental causation in the context of rational choice theory. The author defends psychological aspect of rational explanation against the challenge of contemporary reductive materialism.
Salomon, Dor; Orth, Kim
2015-03-30
Bacteria employ a variety of tools to survive in a competitive environment. Salomon and Orth describe one such tool-the Type 6 Secretion Systems used by bacteria to deliver a variety of toxins into competing cells.
Psychology and the Rationality of Emotion*
Clore, Gerald L.
2011-01-01
Questions addressed by recent psychological research on emotion include questions about how thought shapes emotion and how emotion, in turn, shapes thought. Research on emotion and cognition paints a somewhat different picture than that seen in traditional discussions of passion and reason. This article reviews several aspects of this research, concentrating specifically on three views of rationality: Rationality as Process, Rationality as Product, and Rationality as Outcome.
Kant on empiricism and rationalism
Vanzo, Alberto
2013-01-01
This paper aims to correct some widely held misconceptions concerning Kant's role in the formation of a widespread narrative of early modern philosophy. According to this narrative, which dominated the English-speaking world throughout the twentieth century, the early modern period was characterized by the development of two rival schools: René Descartes's, Baruch Spinoza's, and G. W. Leibniz's rationalism; and John Locke's, George Berkeley's, and David Hume's empiricism. Empiricists and rati...
Davidson on Turing: Rationality Misunderstood?
John-Michael Kuczynski
2005-12-01
Full Text Available Alan Turing advocated a kind of functionalism: A machine M is a thinker provided that it responds in certain ways to certain inputs. Davidson argues that Turing’s functionalism is inconsistent with a cer-tain kind of epistemic externalism, and is therefore false. In Davidson’s view, concepts consist of causal liasons of a certain kind between subject and object. Turing’s machine doesn’t have the right kinds of causal li-asons to its environment. Therefore it doesn’t have concepts. Therefore it doesn’t think. I argue that this reasoning is entirely fallacious. It is true that, in some cases, a causal liason between subject and object is part of one’s concept of that object. Consequently, to grasp certain propositions, one must have certain kids of causal ties to one’s environment. But this means that we must rethink some old views on what rationality is. It does not mean, pace Davidson, that a precondition for being rational is being causally embedded in one’s environment in a certain way. If Tur-ing’s machine isn’t capable of thinking (I leave it open whether it is or is not, that has nothing to do with its lacking certain kinds of causal con-nections to the environment. The larger significance of our discussion is this: rationality consists either in one’s ability to see the bearing of purely existential propositions on one another or rationality is simply not to be understood as the ability see the bearing that propositions have on one another.
Rational approximation of vertical segments
Salazar Celis, Oliver; Cuyt, Annie; Verdonk, Brigitte
2007-08-01
In many applications, observations are prone to imprecise measurements. When constructing a model based on such data, an approximation rather than an interpolation approach is needed. Very often a least squares approximation is used. Here we follow a different approach. A natural way for dealing with uncertainty in the data is by means of an uncertainty interval. We assume that the uncertainty in the independent variables is negligible and that for each observation an uncertainty interval can be given which contains the (unknown) exact value. To approximate such data we look for functions which intersect all uncertainty intervals. In the past this problem has been studied for polynomials, or more generally for functions which are linear in the unknown coefficients. Here we study the problem for a particular class of functions which are nonlinear in the unknown coefficients, namely rational functions. We show how to reduce the problem to a quadratic programming problem with a strictly convex objective function, yielding a unique rational function which intersects all uncertainty intervals and satisfies some additional properties. Compared to rational least squares approximation which reduces to a nonlinear optimization problem where the objective function may have many local minima, this makes the new approach attractive.
Bounded rationality and heterogeneous expectations in macroeconomics
D. Massaro
2012-01-01
This thesis studies the effect of individual bounded rationality on aggregate macroeconomic dynamics. Boundedly rational agents are specified as using simple heuristics in their decision making. An important aspect of the type of bounded rationality described in this thesis is that the population of
Rational Solutions in a Coupled Burgers System
HUANG Ling
2006-01-01
Three types of the rational solutions for a new coupled Burgers system are studied in detail in terms of the reduction and decoupled procedures. The first two types of rational solutions are singular and valid for one type of model parameter c＞0, and another type of rational solutions is nonsingular at any type and valid for another type of model parameter c＜0.
Rational Thinking in School-Based Practice
Clark, Mary Kristen; Flynn, Perry
2011-01-01
Purpose: We reflect on Alan Kamhi's (2011) prologue on balancing certainty and uncertainty as it pertains to school-based practice. Method: In schools, rational thinking depends on effective team processes, much like professional learning communities. We consider the conditions that are required for rational thinking and how rational team dialogue…
Byrnit, Jill; Høgh-Olesen, Henrik; Makransky, Guido
2015-01-01
as sharing in which group members were allowed to co-feed or remove food from the stock of the food possessor, and the introduction of high-value food resulted in more sharing, not less. Food sharing behavior differed between species in that chimpanzees displayed significantly more begging behavior than......All over the world, humans (Homo sapiens) display resource-sharing behavior, and common patterns of sharing seem to exist across cultures. Humans are not the only primates to share, and observations from the wild have long documented food sharing behavior in our closest phylogenetic relatives......, chimpanzees (Pan troglodytes) and bonobos (Pan paniscus). However, few controlled studies have been made where groups of Pan are introduced to food items that may be shared or monopolized by a first food possessor, and very few studies have examined what happens to these sharing patterns if the food...
Rational choice theory and suicide.
Lester, D
1988-12-01
The implications of viewing the decision to kill oneself as a rational choice, based on an analysis of the costs and benefits, were explored. Suicide is but one symptom for an individual in distress to choose, and if suicide is prevented, other symptoms may appear in its place. Similarly, a critical question to be asked in suicide prevention is whether restriction of the availability of one method for suicide (such as detoxifying domestic gas or car exhaust) will result in suicidal individuals switching to a different method for suicide or to a different symptom of distress.
Unconventional protein secretion.
Ding, Yu; Wang, Juan; Wang, Junqi; Stierhof, York-Dieter; Robinson, David G; Jiang, Liwen
2012-10-01
It is generally believed that protein secretion or exocytosis is achieved via a conventional ER (endoplasmic reticulum)-Golgi-TGN (trans-Golgi network)-PM (plasma membrane) pathway in the plant endomembrane system. However, such signal peptide (SP)-dependent protein secretion cannot explain the increasing number of SP-lacking proteins which are found outside of the PM in plant cells. The process by which such leaderless secretory proteins (LSPs) gain access to the cell exterior is termed unconventional protein secretion (UPS) and has been well-studied in animal and yeast cells, but largely ignored by the plant community. Here, we review the evidence for UPS in plants especially in regard to the recently discovered EXPO (exocyst-positive-organelle).
Shared decision-making and patient autonomy.
Sandman, Lars; Munthe, Christian
2009-01-01
In patient-centred care, shared decision-making is advocated as the preferred form of medical decision-making. Shared decision-making is supported with reference to patient autonomy without abandoning the patient or giving up the possibility of influencing how the patient is benefited. It is, however, not transparent how shared decision-making is related to autonomy and, in effect, what support autonomy can give shared decision-making. In the article, different forms of shared decision-making are analysed in relation to five different aspects of autonomy: (1) self-realisation; (2) preference satisfaction; (3) self-direction; (4) binary autonomy of the person; (5) gradual autonomy of the person. It is argued that both individually and jointly these aspects will support the models called shared rational deliberative patient choice and joint decision as the preferred versions from an autonomy perspective. Acknowledging that both of these models may fail, the professionally driven best interest compromise model is held out as a satisfactory second-best choice.
The stand-alone test and decreasing serial cost sharing
Hougaard, Jens Leth; Thorlund-Petersen, Lars
2000-01-01
The rule of decreasing serial cost sharing defined in de Frutos [1] over the class of concave cost functions may violate the important stand-alone test. Sufficient conditions for the test to be satisfied are given, in terms of individual rationality as well as coalitional stability. These conditi....... These conditions restrict the shape of the cost function and the distribution of demands...
Continuous Variable Quantum State Sharing via Quantum Disentanglement
Lance, A M; Bowen, W P; Sanders, B C; Tyc, T; Ralph, T C; Lam, P K; Lance, Andrew M.; Symul, Thomas; Bowen, Warwick P.; Sanders, Barry C.; Tyc, Tomas; Ralph, Timothy C.; Lam, Ping Koy
2004-01-01
Quantum state sharing is a protocol where perfect reconstruction of quantum states is achieved with incomplete or partial information in a multi-partite quantum networks. Quantum state sharing allows for secure communication in a quantum network where partial information is lost or acquired by malicious parties. This protocol utilizes entanglement for the secret state distribution, and a class of "quantum disentangling" protocols for the state reconstruction. We demonstrate a quantum state sharing protocol in which a tripartite entangled state is used to encode and distribute a secret state to three players. Any two of these players can collaborate to reconstruct the secret state, whilst individual players obtain no information. We investigate a number of quantum disentangling processes and experimentally demonstrate quantum state reconstruction using two of these protocols. We experimentally measure a fidelity, averaged over all reconstruction permutations, of F = 0.73. A result achievable only by using quan...
A Comparison of Rational Emotive Therapy and Tibetan Buddhism: Albert Ellis and the Dalai Lama
Holt, Susan A; Austad, Carol Shaw
2013-01-01
This article explores conceptual and methodological similarities between Rational Emotive Behavior Therapy (REBT) and Tibetan Buddhism (TB). The authors examine some of the values and concepts they share. They compare the two systems on a number of issues: philosophical underpinnings, concepts of what causes human psychopathology, techniques to…
The relational nature of rational numbers
Bruce Brown
2015-06-01
Full Text Available It is commonly accepted that the knowledge and learning of rational numbers is more complex than that of the whole number field. This complexity includes the broader range of application of rational numbers, the increased level of technical complexity in the mathematical structure and symbol systems of this field and the more complex nature of many conceptual properties of the rational number field. Research on rational number learning is divided as to whether children’s difficulties in learning rational numbers arise only from the increased complexity or also include elements of conceptual change. This article argues for a fundamental conceptual difference between whole and rational numbers. It develops the position that rational numbers are fundamentally relational in nature and that the move from absolute counts to relative comparisons leads to a further level of abstraction in our understanding of number and quantity. The argument is based on a number of qualitative, in-depth research projects with children and adults. These research projects indicated the importance of such a relational understanding in both the learning and teaching of rational numbers, as well as in adult representations of rational numbers on the number line. Acknowledgement of such a conceptual change could have important consequences for the teaching and learning of rational numbers.
Reappraisal of Rational Choice Theory
Katalin Martinas
2013-01-01
Full Text Available The value of rational choice theory (RCT for the social sciences has long been contested. Much time has been spent by economists and critics on the pervasive but elusive concept of rationality. The critiques mainly challenge the basis of the utility theorem. Several articles on the misuse of mathematics in economics have already appeared in the literature. As N. Bouleau stated, “On several occasions, however, one feels that the criticism is that the math is being misused and should be developed in some other direction (e.g. a statistical analysis of the financial tendencies that polarize wealth and income, or a study of the positive feedback mechanisms, etc.. This leaves certain dissatisfaction – on a philosophical level.” The aim of this paper is to present a decision theory, yields intention (logos and valuation (existence. Here we present a new mathematical representation of RCT, which leads to a dynamic economic theory. We discuss the philosophical or meta-economical problems, which are needed for the successful applications of mathematics.
Rational approximations to fluid properties
Kincaid, J. M.
1990-05-01
The purpose of this report is to summarize some results that were presented at the Spring AIChE meeting in Orlando, Florida (20 March 1990). We report on recent attempts to develop a systematic method, based on the technique of rational approximation, for creating mathematical models of real-fluid equations of state and related properties. Equation-of-state models for real fluids are usually created by selecting a function tilde p(T,rho) that contains a set of parameters (gamma sub i); the (gamma sub i) is chosen such that tilde p(T,rho) provides a good fit to the experimental data. (Here p is the pressure, T the temperature and rho is the density). In most cases, a nonlinear least-squares numerical method is used to determine (gamma sub i). There are several drawbacks to this method: one has essentially to guess what tilde p(T,rho) should be; the critical region is seldom fit very well and nonlinear numerical methods are time consuming and sometimes not very stable. The rational approximation approach we describe may eliminate all of these drawbacks. In particular, it lets the data choose the function tilde p(T,rho) and its numerical implementation involves only linear algorithms.
Fjalland, Emmy Laura Perez
In urban areas sharing cultures, services and economies are rising. People share, rent and recycle their homes, cars, bikes, rides, tools, cloths, working space, knowhow and so on. The sharing culture can be understood as mobilities (Kesselring and Vogl 2013) of goods, values and ideas reshaping...... our cities. The sharing economy has the power to democratise access the urban space, resources and raw materials (Steen Nielsen 2008; Harvey 2000); it holds the ability to change the current dominant understandings and structures of economy and growth (Steen Nielsen 2008); solve emerging environmental...... and trust. (Thomsen 2013; Bauman 2000; Beck 1992; Giddens 1991). The sharing economy is currently hyper trendy but before claiming capitalism as dead we need to understand the basics of the sharing economies and cultures asking who can share and what will we share. Furthermore it is crucial to study what...
Charting Secrets Stop Reading Start Practicing
Bedford, Louise
2012-01-01
It is a common myth that the sharemarket is a fast ticket to the easy life. Buy a few shares and watch them go up. Call your broker for up-to-the-minute price information as you drive the Porsche to the golf club. Yell 'Sell! Sell! Sell' into your mobile as you ski through the Swiss Alps. Nothing could be further from the truth. Louise Bedford believes that the only way to be successful in the market is to spend time studying and putting in the hard work, just like any other job. With this in mind, she has written Charting Secrets. Not just another trading book, Charting Secrets is a workbook
Secrets of Successful Homeschooling
Rivero, Lisa
2011-01-01
Parents who homeschool gifted children often find the daily practice of home education very different from what they had imagined. Gifted children are complex in both personality and learning styles. Parents who say that homeschooling works well for their gifted children have learned from others or discovered on their own several secrets that make…
Alejandro Esteller
2008-01-01
The formation of bile depends on the structural and functional integrity of the bile-secretory apparatus and its impairment,in different situations,results in the syndrome of cholestasis.The structural bases that permit bile secretion as well as various aspects related with its composition and flow rate in physiological conditions will first be reviewed.Canalicular bile is produced by polarized hepatocytes that hold transporters in their basolateral (sinusoidal) and apical (canalicular) plasma membrane.This review summarizes recent data on the molecular determinants of this primary bile formation.The major function of the biliary tree is modification of canalicular bile by secretory and reabsorptive processes in bileduct epithelial cells (cholangiocytes) as bile passes through bile ducts.The mechanisms of fluid and solute transport in cholangiocytes will also be discussed.In contrast to hepatocytes where secretion is constant and poorly controlled,cholangiocyte secretion is regulated by hormones and nerves.A short section dedicated to these regulatory mechanisms of bile secretion has been included.The aim of this revision was to set the bases for other reviews in this series that will be devoted to specific issues related with biliary physiology and pathology.
Dorman, H. L.; And Others
1981-01-01
Describes materials and procedures for an experiment utilizing a live dog to demonstrate: (1) physiology of the salivary gland; (2) parasympathetic control of the salivary gland; (3) influence of varying salivary flow rates on sodium and potassium ions, osmolarity and pH; and (4) salivary secretion as an active process. (DS)
Satisfaction and 'comparison sharing'
Amilon, Anna
2009-01-01
the probability of satisfaction. Results show that comparison sharing impacts satisfaction for women, and that those women who share more equally than their peers are more likely to be satisfied, whereas comparison sharing has no influence on satisfaction for men. Also, parents are less likely to be satisfied...
Geometric Rationalization for Freeform Architecture
Jiang, Caigui
2016-06-20
The emergence of freeform architecture provides interesting geometric challenges with regards to the design and manufacturing of large-scale structures. To design these architectural structures, we have to consider two types of constraints. First, aesthetic constraints are important because the buildings have to be visually impressive. Sec- ond, functional constraints are important for the performance of a building and its e cient construction. This thesis contributes to the area of architectural geometry. Specifically, we are interested in the geometric rationalization of freeform architec- ture with the goal of combining aesthetic and functional constraints and construction requirements. Aesthetic requirements typically come from designers and architects. To obtain visually pleasing structures, they favor smoothness of the building shape, but also smoothness of the visible patterns on the surface. Functional requirements typically come from the engineers involved in the construction process. For exam- ple, covering freeform structures using planar panels is much cheaper than using non-planar ones. Further, constructed buildings have to be stable and should not collapse. In this thesis, we explore the geometric rationalization of freeform archi- tecture using four specific example problems inspired by real life applications. We achieve our results by developing optimization algorithms and a theoretical study of the underlying geometrical structure of the problems. The four example problems are the following: (1) The design of shading and lighting systems which are torsion-free structures with planar beams based on quad meshes. They satisfy the functionality requirements of preventing light from going inside a building as shad- ing systems or reflecting light into a building as lighting systems. (2) The Design of freeform honeycomb structures that are constructed based on hex-dominant meshes with a planar beam mounted along each edge. The beams intersect without
Mehtap Sahingoz
2013-02-01
Full Text Available ABSTRACT Objective: At this study to be aimed to assess status of the knowledge of nurses who working in public and private health institutions in Sivas province use of medication fort he treatment during their illnesses and patients and the attitudes of rational drug application. Matherials and methods: the researc planned to attend 750 nurses but it has been completed with participation of 641 nurses (Reaching rate 85,5%. This is a descriptive and cross-sectional study. in the study data were collected with a questionaire, percentages stated and chi square test was used for analysis. Results: %95,3 of nurses were females and mean age of them 29.21±4.85 years. The rate of contacting a doktor in case of illness is higher in 39.1% of nurses in the 21-30 age group and 48.6% of nurses working in primary care institutions. The level of self-treating is higher in 45.5 % of nurses working less than a year in profession .In the case of illness, 53% of nurses stated that they had left the medicine when signs of disease over. %98.8 of nurses expressed that they know effects of drugs used and 99.1% of them stated they know the side effects of drugs used. The entire group of postgraduate education status stated that they have not received the drug recommended by others. The level of suggesting a drug to someone else fort he same disease is higher in 65.8% of the group 31 years and older and group working over 40 hours per week. It were determined that used in consultation with the physician 65.2% of nurses antibiotics, 87.5% of them weiht loss drug and 82.7% of them contraceptive . 99.5% of the nurses have expressed that they inform to patients about use of their medications. Among the issues that expressed informations took place the application form of drugs (51.0 %and information of need to consult one if deemed one unexpected effect (59.6% . Also has been identified that of nurses acquired inform about drugs from drug book (vademecum (87.5 % and they
Rational Choice and the Framing of Decisions.
1986-05-29
Yellen, J. (1985). Can small deviations from rationality make significant differences to economic equilibria? American Economic Review , 75, 708-720...theory of choice and the preference reversal phenomenon. American Economic Review , 69, 623-38. Hagen, 0. (1979). Towards a positive theory of preferences...Publishing Co. Haltiwanger, J. & Waldman, M. (1985). Rational expectations and the limits of rationality: An analysis of heterogeneity. American Economic Review , 75
Rational Addiction Evidence From Carbonated Soft Drinks
Xiaoou, Liu
2009-01-01
This paper applies the Becker-Murphy (1988) theory of rational addiction to the case of carbonated soft drinks, using a time-varying parameter model and scanner data from 46 U.S. cities. Empirical results provide strong evidence that carbonated soft drinks are rationally addictive, thus opening the door to taxation and regulation. Taking rational addition into account, estimated demand elasticities are much lower than previous estimates using scanner data.
Hegazy, Wael Abdel Halim; Xu, Xin; Metelitsa, Leonid; Hensel, Michael
2012-03-01
Live attenuated strains of Salmonella enterica have a high potential as carriers of recombinant vaccines. The type III secretion system (T3SS)-dependent translocation of S. enterica can be deployed for delivery of heterologous antigens to antigen-presenting cells. Here we investigated the efficacy of various effector proteins of the Salmonella pathogenicity island (SPI2)-encoded T3SS for the translocation of model antigens and elicitation of immune responses. The SPI2 T3SS effector proteins SifA, SteC, SseL, SseJ, and SseF share an endosomal membrane-associated subcellular localization after translocation. We observed that all effector proteins could be used to translocate fusion proteins with the model antigens ovalbumin and listeriolysin into the cytosol of host cells. Under in vitro conditions, fusion proteins with SseJ and SteC stimulated T-cell responses that were superior to those triggered by fusion proteins with SseF. However, in mice vaccinated with Salmonella carrier strains, only fusion proteins based on SseJ or SifA elicited potent T-cell responses. These data demonstrate that the selection of an optimal SPI2 effector protein for T3SS-mediated translocation is a critical parameter for the rational design of effective Salmonella-based recombinant vaccines.
The structure of bivariate rational hypergeometric functions
Cattani, Eduardo; Villegas, Fernando Rodriguez
2009-01-01
We describe the structure of all codimension-two lattice configurations $A$ which admit a stable rational $A$-hypergeometric function, that is a rational function $F$ all whose partial derivatives are non zero, and which is a solution of the $A$-hypergeometric system of partial differential equations defined by Gel'fand, Kapranov and Zelevinsky. We show, moreover, that all stable rational $A$-hypergeometric functions may be described by toric residues and apply our results to study the rationality of bivariate series whose coefficients are quotients of factorials of linear forms.
RATIONAL PHARMACOTHERAPY IN TAKOTSUBO CARDIOMYOPATHY
S. Marchev
2012-01-01
Full Text Available Rational pharmacotherapy in Takotsubo cardiomyopathy is based on clinical picture and data of functional and laboratory investigations of concrete patient. In patients with hypotension and moderate-to-severe left ventricle outflow tract obstruction inotropic agents must not to be used because they can worsen the degree of obstruction. In these patients beta blockers can improve hemodynamics by causing resolution of the obstruction. If intraventricular thrombus is detected, anticoagulation for at least 3 months is recommended. The duration of anticoagulant therapy may be modified depending on the extent of cardiac function recovery and thrombus resolution. For patients without thrombus but with severe left ventricular dysfunction, anticoagulation is recommended until the akinesis or dyskinesis has resolved but not more than 3 months.
Dual Rationality and Deliberative Agents
Debenham, John; Sierra, Carles
Human agents deliberate using models based on reason for only a minute proportion of the decisions that they make. In stark contrast, the deliberation of artificial agents is heavily dominated by formal models based on reason such as game theory, decision theory and logic—despite that fact that formal reasoning will not necessarily lead to superior real-world decisions. Further the Nobel Laureate Friedrich Hayek warns us of the ‘fatal conceit’ in controlling deliberative systems using models based on reason as the particular model chosen will then shape the system’s future and either impede, or eventually destroy, the subtle evolutionary processes that are an integral part of human systems and institutions, and are crucial to their evolution and long-term survival. We describe an architecture for artificial agents that is founded on Hayek’s two rationalities and supports the two forms of deliberation used by mankind.
Essays on Rational Portfolio Theory
Nielsen, Simon Ellersgaard
This dissertation is comprised of five research papers written during the period January 2013 -December 2015. Their abstracts are: The Fundamental Theorem of Derivative Trading. When estimated volatilities are not inperfect agreement with reality, delta hedged option portfolios will incur a non...... is proportional to volatility, we can deriveclosed form expressions for the optimal portfolio using the formalism of Hamilton-JacobixiiiBellman. We also perform an empirical investigation, which strongly suggests that there inreality are no tangible welfare gains associated with hedging stochastic volatility...... in a bondstockeconomy. Stochastic Volatility for Utility Maximisers Part II. Using martingale methods we derivebequest optimising portfolio weights for a rational investor who trades in a bond-stockderivativeeconomy characterised by a generic stochastic volatility model. For illustrativepurposes we then proceed...
Are Secrets Immoral? The Construction of Secrets in Everyday Conversation.
Gunthner, Susanne; Luckmann, Thomas
1998-01-01
Investigates the communicative treatment of secrets, presenting examples from recorded communicative interactions in a wide range of social milieus and settings in which the participants revealed knowledge of secrets, tried to dig out old secrets without appearing to be doing so, and occasionally, appeared to be hiding some items of knowledge from…
Kalberg, Stephen
1980-01-01
Explores rationality in Max Weber's works and identifies four types of rationality which play major roles in his writing--practical, theoretical, substantive, and formal. Implications for society and education are discussed. (DB)
The application of rational design on phospholipase A(2) inhibitors.
Mouchlis, V D; Barbayianni, E; Mavromoustakos, T M; Kokotos, G
2011-01-01
The phospholipase A(2) (PLA(2)) superfamily consists of different groups of enzymes which are characterized by their ability to catalyze the hydrolysis of the sn-2 ester bond in a variety of phospholipid molecules. The products of PLA(2s) activity play divergent roles in a variety of physiological processes. There are four main types of PLA(2s): the secreted PLA(2s) (sPLA(2s)), the cytosolic PLA(2s) (cPLA(2s)), the calcium-independent PLA(2s) (iPLA(2)) and the lipoprotein-associated PLA(2s) (LpPLA(2s)). Various potent and selective PLA2 inhibitors have been reported up to date and have provided outstanding support in understanding the mechanism of action and elucidating the function of these enzymes. The current review focuses on the implementation of rational design through computer-aided drug design (CADD) on the discovery and development of new PLA(2) inhibitors.
Rational Solution To Income Gap
无
2006-01-01
While enjoying an economic boom, China has seen a widening income gap that has appeared like a chasm between its urban and rural citizens. What are the deep roots of this situation and what is the best way to deal with it? Ding Yuanzhu, researcher at the Macro-Economic Research Institute of the National Development and Reform Commission, shares his views on this issue in an article published in Wen Hui Bao. Excerpts follow:
Secret-Key Generation using Correlated Sources and Channels
Khisti, Ashish; Wornell, Gregory
2009-01-01
We study the problem of generating a shared secret key between two terminals in a joint source-channel setup -- the sender communicates to the receiver over a discrete memoryless wiretap channel and additionally the terminals have access to correlated discrete memoryless source sequences. We establish lower and upper bounds on the secret-key capacity. These bounds coincide, establishing the capacity, when the underlying channel consists of independent, parallel and reversely degraded wiretap channels. In the lower bound, the equivocation terms of the source and channel components are functionally additive. The secret-key rate is maximized by optimally balancing the the source and channel contributions. This tradeoff is illustrated in detail for the Gaussian case where it is also shown that Gaussian codebooks achieve the capacity. When the eavesdropper also observes a source sequence, the secret-key capacity is established when the sources and channels of the eavesdropper are a degraded version of the legitima...
Extracellular secretion of recombinant proteins
Linger, Jeffrey G.; Darzins, Aldis
2014-07-22
Nucleic acids encoding secretion signals, expression vectors containing the nucleic acids, and host cells containing the expression vectors are disclosed. Also disclosed are polypeptides that contain the secretion signals and methods of producing polypeptides, including methods of directing the extracellular secretion of the polypeptides. Exemplary embodiments include cellulase proteins fused to secretion signals, methods to produce and isolate these polypeptides, and methods to degrade lignocellulosic biomass.
The Quantum Affine Origin of the AdS/CFT Secret Symmetry
de Leeuw, Marius; Torrielli, Alessandro
2011-01-01
We find a new quantum affine symmetry of the S-matrix of the one-dimensional Hubbard chain. We show that this symmetry originates from the quantum affine superalgebra U_q(gl(2|2)), and in the rational limit exactly reproduces the secret symmetry of the AdS/CFT worldsheet S-matrix.
Ionela Mihai
2010-07-01
Full Text Available L’émission Bucarest, strictement secret représente un documentaire organisésous la forme d’une série télé, qui dépeint le Bucarest à partir de deux perspectives: de l’histoire, de la conte et du lieu. La valeur d’une cité réside dans l’existence d’une mystique, d’un romantisme abscons, à part et des caractères empruntés de drames de Shakespeare, mystérieux, serrés d’angoisse et des secrets qui assombrissent leur existence. Par conséquence, le rôle du metteur en scène est de dévoiler leur vraie identité et de remettre en place, autant que possible, la vérité.
Secret Key Crypto Implementations
Bertoni, Guido Marco; Melzani, Filippo
This chapter presents the algorithm selected in 2001 as the Advanced Encryption Standard. This algorithm is the base for implementing security and privacy based on symmetric key solutions in almost all new applications. Secret key algorithms are used in combination with modes of operation to provide different security properties. The most used modes of operation are presented in this chapter. Finally an overview of the different techniques of software and hardware implementations is given.
Lomas, S J; Rice, C L
2001-01-01
In his essay on bedside rationing, Peter Ubel argues that in an era of rising healthcare costs, it is time to relax the patient-centered ethic of physicians as unconditional patient advocates so they can individualize rationing decisions. This paper raises several concerns with the arguments and the examples he provides to make his case. First, he overlooks cost-effectiveness when making medical spending decisions. Second, his examples of wasteful, unproven and potentially harmful interventions call for physician education, not rationing, as he suggests. Third, informed patients can play a role in lowering costs through shared decision making. Fourth, individualized rationing decisions will worsen already pervasive disparities in medical care. The paper envisions the ideal cost-conscious physician as one who is knowledgeable about cost-effective practices, avoids unproven interventions whenever possible, and facilitates shared decision making through patient education. Such an individual would not, however, withhold interventions of proven benefit except when accommodating a patient's preferences for a particular therapy. The doctor and patient can only work together within the constraints of system-wide rationing if the fiduciary relationship is never violated.
Rationality and Belief in Learning Mathematics
Brown, Tony
2016-01-01
This paper argues that rationality and belief are mutually formative dimensions of school mathematics, where each term is more politically embedded than often depicted in the field of mathematics education research. School mathematics then presents not so much rational mathematical thought distorted by irrational beliefs but rather a particular…
Linear parameter estimation of rational biokinetic functions
Doeswijk, T.G.; Keesman, K.J.
2009-01-01
For rational biokinetic functions such as the Michaelis-Menten equation, in general, a nonlinear least-squares method is a good estimator. However, a major drawback of a nonlinear least-squares estimator is that it can end up in a local minimum. Rearranging and linearizing rational biokinetic
曹俊鹏; 侯伯宇; 岳瑞宏
2001-01-01
We propose the eigenstates and eigenvalues of Hamiltonians of the rational SU(N) Gaudin model based onthe quasi-classical limit of the SU ( N) chain under the periodic boundary condition. Using the quantum inversescattering method, we also obtain the eigenvalues of the generation function of the rational SU ( N) Gaudin model.
Empirical Rationality in the Stock Market
Raahauge, Peter
2003-01-01
for this empiricalrationality on part of the agent, the resulting empirical model assignslikelihood to the data actually observed, unlike in the unmodified rational expectationscase. A Lucas (1978)-type asset pricing model which incorporatesempirical rationality is constructed and estimated using U.S. stock data...
Counting rational points on cubic curves
HEATH-BROWN; Roger; TESTA; Damiano
2010-01-01
We prove upper bounds for the number of rational points on non-singular cubic curves defined over the rationals.The bounds are uniform in the curve and involve the rank of the corresponding Jacobian.The method used in the proof is a combination of the "determinant method" with an m-descent on the curve.
Is facet analysis based on rationalism?
Hjørland, Birger
2014-01-01
, rationalism, historicism/hermeneutics, or pragmatism/critical theory (of which only the last position fully acknowledges the non-neutrality of knowledge organisation). Ranganathan – and the whole facet-analytic school – has formerly been exemplified as a rather clear example of rationalism. Some have objected...
Are Grade Expectations Rational? A Classroom Experiment
Hossain, Belayet; Tsigaris, Panagiotis
2015-01-01
This study examines students' expectations about their final grade. An attempt is made to determine whether students form expectations rationally. Expectations in economics, rational or otherwise, carry valuable information and have important implications in terms of both teaching effectiveness and the role of grades as an incentive structure for…
The Problem of Rational Moral Enlistment
Tillson, John
2017-01-01
How can one bring children to recognize the requirements of morality without resorting only to non-rational means of persuasion (i.e. what rational ground can be offered to children for their moral enlistment)? Michael Hand has recently defended a foundationalist approach to answering this question and John White has responded by (a) criticizing…
Neurophysiology and Rationality in Political Thinking.
Peterson, Steven A.
Research both in cognitive psychology and psychobiology suggests that political behavior is often less rational than individuals believe it to be. Information processing, memory, and decision making are interlinked processes. Studies in cognitive psychology reveal that even though decision making requires rationality, individuals often adopt…
Rationality and Belief in Learning Mathematics
Brown, Tony
2016-01-01
This paper argues that rationality and belief are mutually formative dimensions of school mathematics, where each term is more politically embedded than often depicted in the field of mathematics education research. School mathematics then presents not so much rational mathematical thought distorted by irrational beliefs but rather a particular…
Rationality : a social-epistemology perspective
Wenmackers, Sylvia; Vanpoucke, Danny E. P.; Douven, Igor
2014-01-01
Both in philosophy and in psychology, human rationality has traditionally been studied from an “individualistic” perspective. Recently, social epistemologists have drawn attention to the fact that epistemic interactions among agents also give rise to important questions concerning rationality. In pr
Avital, Michel; Carroll, John M.; Hjalmarsson, Anders
2015-01-01
The sharing economy is spreading rapidly worldwide in a number of industries and markets. The disruptive nature of this phenomenon has drawn mixed responses ranging from active conflict to adoption and assimilation. Yet, in spite of the growing attention to the sharing economy, we still do not know...... much about it. With the abundant enthusiasm about the benefits that the sharing economy can unleash and the weekly reminders about its dark side, further examination is required to determine the potential of the sharing economy while mitigating its undesirable side effects. The panel will join...... the ongoing debate about the sharing economy and contribute to the discourse with insights about how digital technologies are critical in shaping this turbulent ecosystem. Furthermore, we will define an agenda for future research on the sharing economy as it becomes part of the mainstream society as well...
Factors Impacting Knowledge Sharing
Schulzmann, David; Slepniov, Dmitrij
The purpose of this paper is to examine various factors affecting knowledge sharing at the R&D center of a Western MNE in China. The paper employs qualitative methodology and is based on the action research and case study research techniques. The findings of the paper advance our understanding...... about factors that affect knowledge sharing. The main emphasis is given to the discussion on how to improve knowledge sharing in global R&D organizations....
Facilitating Knowledge Sharing
Holdt Christensen, Peter
Abstract This paper argues that knowledge sharing can be conceptualized as different situations of exchange in which individuals relate to each other in different ways, involving different rules, norms and traditions of reciprocity regulating the exchange. The main challenge for facilitating...... and the intermediaries regulating the exchange, and facilitating knowledge sharing should therefore be viewed as a continuum of practices under the influence of opportunistic behaviour, obedience or organizational citizenship behaviour. Keywords: Knowledge sharing, motivation, organizational settings, situations...
Facilitating Knowledge Sharing
Holdt Christensen, Peter
2005-01-01
Abstract This paper argues that knowledge sharing can be conceptualized as different situations of exchange in which individuals relate to each other in different ways, involving different rules, norms and traditions of reciprocity regulating the exchange. The main challenge for facilitating knowledge sharing is to ensure that the exchange is seen as equitable for the parties involved, and by viewing the problems of knowledge sharing as motivational problems situated in different organization...
Generalized NLS Hierarchies from Rational $W$ Algebras
Toppan, F
1994-01-01
Finite rational $\\cw$ algebras are very natural structures appearing in coset constructions when a Kac-Moody subalgebra is factored out. In this letter we address the problem of relating these algebras to integrable hierarchies of equations, by showing how to associate to a rational $\\cw$ algebra its corresponding hierarchy. We work out two examples: the $sl(2)/U(1)$ coset, leading to the Non-Linear Schr\\"{o}dinger hierarchy, and the $U(1)$ coset of the Polyakov-Bershadsky $\\cw$ algebra, leading to a $3$-field representation of the KP hierarchy already encountered in the literature. In such examples a rational algebra appears as algebra of constraints when reducing a KP hierarchy to a finite field representation. This fact arises the natural question whether rational algebras are always associated to such reductions and whether a classification of rational algebras can lead to a classification of the integrable hierarchies.
Dynamic secrets in communication security
Xiao, Sheng; Towsley, Donald
2013-01-01
Dynamic secrets are constantly generated and updated from messages exchanged between two communication users. When dynamic secrets are used as a complement to existing secure communication systems, a stolen key or password can be quickly and automatically reverted to its secret status without disrupting communication. 'Dynamic Secrets in Communication Security' presents unique security properties and application studies for this technology. Password theft and key theft no longer pose serious security threats when parties frequently use dynamic secrets. This book also illustrates that a dynamic
Mercè Crosas
2012-01-01
Full Text Available From the early days of modern science through this century of Big Data, data sharing has enabled some of the greatest advances in science. In the digital age, technology can facilitate more effective and efficient data sharing and preservation practices, and provide incentives for making data easily accessible among researchers. At the Institute for Quantitative Social Science at Harvard University, we have developed an open-source software to share, cite, preserve, discover and analyze data, named the Dataverse Network. We share here the project’s motivation, its growth and successes, and likely evolution.
Phenomenology of experiential sharing
León, Felipe; Zahavi, Dan
2016-01-01
The chapter explores the topic of experiential sharing by drawing on the early contributions of the phenomenologists Alfred Schutz and Gerda Walther. It is argued that both Schutz and Walther support, from complementary perspectives, an approach to experiential sharing that has tended...... to be overlooked in current debates. This approach highlights specific experiential interrelations taking place among individuals who are jointly engaged and located in a common environment, and situates this type of sharing within a broader and richer spectrum of sharing phe- nomena. Whereas Schutz’ route...
Phenomenology of experiential sharing
León, Felipe; Zahavi, Dan
2016-01-01
The chapter explores the topic of experiential sharing by drawing on the early contributions of the phenomenologists Alfred Schutz and Gerda Walther. It is argued that both Schutz and Walther support, from complementary perspectives, an approach to experiential sharing that has tended to be overl......The chapter explores the topic of experiential sharing by drawing on the early contributions of the phenomenologists Alfred Schutz and Gerda Walther. It is argued that both Schutz and Walther support, from complementary perspectives, an approach to experiential sharing that has tended...
Rationality, institutions and environmental policy
Vatn, Arild [Department of Economics and Resource Management, Norwegian University of Life Sciences, Aas (Norway)
2005-11-01
This paper is about how institutions determine choices and the importance of this for environmental policy. The model of individual rational choice from neoclassical economics is compared with the model of socially determined behavior. While in the first case, institutions are either exempted from or understood as mere economizing constraints on behavior, the latter perspective views institutions as basic structures necessary also to enable people to act. The paper develops a way to integrate the individualistic model into the wider perspective of social constructivism by viewing it as a special form of such construction. On the basis of this synthesis three issues with relevance for environmental economics are discussed. First, the role of institutional factors in the process of preference formation is emphasized. Next, the role of institutions for the choice of desired states of the environment is analyzed. Finally, the effect of various policy instruments to motivate people to produce these states is discussed. It is concluded that the core policy issue is to determine which institutional frameworks are most reasonable to apply to which kind of problem. Issues, which from the perspective of neoclassical economics are pure technical, become serious value questions if understood from an institutional perspective.
[RATIONAL ASPECTS OF BACTERIOPHAGES USE].
Vakarina, A A; Kataeva, L V; Karpukhina, N F
2015-01-01
Analysis of existing aspects of bacteriophage use and study features of their lytic activity by using various techniques. Effect of monophages and associated bacteriophages (staphylococci, piopolyvalent and piocombined, intestiphage, pneumonia klebsiella and polyvalent klebsiella produced by "Microgen") was studied with 380 strains of Staphylococcus aureus and 279 cultures of Klebsiella pneumoniae in liquid and solid nutrient media. From patients with intestinal disorder, sensitivity was analyzed to 184 strains of Salmonella genus bacteria 18 serological variants to salmonella bacteriophages, 137 strains of Escherichia coli (lactose-negative, hemolytic), as well as some members of OKA groups (21 serovars) to coli-proteic and piopolyvalent bacteriophages. Lytic ability of the piobacteriophage against Klebsiella and Proteus genus bacteria was determined. Staphylococcus aureus was sensitive to staphylococcus bacteriophage in 71.6% of cases and to piobacteriophage--in 86.15% of cases. A 100% lytic ability of salmonella bacteriophage against Salmonella spp. was established. Sensitivity of E. coli of various serogroups to coli-proteic and piobacteriophage was 66 - 100%. Klebsiella, Proteus genus bacteria were sensitive to piobacteriophage in only 35% and 43.15% of cases, respectively. A more rational use of bacteriophages is necessary: development of a technique, evaluation of sensitivity of bacteria to bacteriophage, introduction of corrections into their production (expansion of bacteriophage spectra, determination and indication of their concentration in accompanying documents).
Autotransporter protein secretion.
Tame, Jeremy R H
2011-12-01
Autotransporter proteins are a large family of virulence factors secreted from Gram-negative bacteria by a unique mechanism. First described in the 1980s, these proteins have a C-terminal region that folds into a β-barrel in the bacterial outer membrane. The so-called passenger domain attached to this barrel projects away from the cell surface and may be liberated from the cell by self-cleavage or surface proteases. Although the majority of passenger domains have a similar β-helical structure, they carry a variety of sub-domains, allowing them to carry out widely differing functions related to pathogenesis. Considerable biochemical and structural characterisation of the barrel domain has shown that 'autotransporters' in fact require a conserved and essential protein complex in the outer membrane for correct folding. Although the globular domains of this complex projecting into the periplasmic space have also been structurally characterised, the overall secretion pathway of the autotransporters remains highly puzzling. It was presumed for many years that the passenger domain passed through the centre of the barrel domain to reach the cell surface, driven at least in part by folding. This picture is complicated by conflicting data, and there is currently little hard information on the true nature of the secretion intermediates. As well as their medical importance therefore, autotransporters are proving to be an excellent system to study the folding and membrane insertion of outer membrane proteins in general. This review focuses on structural aspects of autotransporters; their many functions in pathogenesis are beyond its scope.
Avital, Michel; Carroll, John M.; Hjalmarsson, Anders;
2015-01-01
The sharing economy is spreading rapidly worldwide in a number of industries and markets. The disruptive nature of this phenomenon has drawn mixed responses ranging from active conflict to adoption and assimilation. Yet, in spite of the growing attention to the sharing economy, we still do not kn...
Limitations to sharing entanglement
Kim, Jeong San; Sanders, Barry C
2011-01-01
We discuss limitations to sharing entanglement known as monogamy of entanglement. Our pedagogical approach commences with simple examples of limited entanglement sharing for pure three-qubit states and progresses to the more general case of mixed-state monogamy relations with multiple qudits.
Nekovee, Maziar; Rudd, Richard
2017-01-01
In this paper an overview is given of the current status of 5G industry standards, spectrum allocation and use cases, followed by initial investigations of new opportunities for spectrum sharing in 5G using cognitive radio techniques, considering both licensed and unlicensed scenarios. A particular attention is given to sharing millimeter-wave frequencies, which are of prominent importance for 5G.
Turkat, Ira Daniel
2002-01-01
Joint custody of children is the most prevalent court ordered arrangement for families of divorce. A growing body of literature indicates that many parents engage in behaviors that are incompatible with shared parenting. This article provides specific criteria for a definition of the Shared Parenting Dysfunction. Clinical aspects of the phenomenon…
Thurrott, Paul
2012-01-01
Tips, tricks, treats, and secrets revealed on Windows 8 Microsoft is introducing a major new release of its Windows operating system, Windows 8, and what better way to learn all its ins and outs than from two internationally recognized Windows experts and Microsoft insiders, authors Paul Thurrott and Rafael Rivera? They cut through the hype to get at useful information you'll not find anywhere else, including what role this new OS plays in a mobile and tablet world. Regardless of your level of knowledge, you'll discover little-known facts about how things work, what's new and different, and h
Senior doctors' opinions of rational suicide.
Ginn, Stephen; Price, Annabel; Rayner, Lauren; Owen, Gareth S; Hayes, Richard D; Hotopf, Matthew; Lee, William
2011-12-01
The attitudes of medical professionals towards physician assisted dying have been widely discussed. Less explored is the level of agreement among physicians on the possibility of 'rational suicide'-a considered suicide act made by a sound mind and a precondition of assisted dying legislation. To assess attitudes towards rational suicide in a representative sample of senior doctors in England and Wales. A postal survey was conducted of 1000 consultants and general practitioners randomly selected from a commercially available database. The main outcome of interest was level of agreement with a statement about rational suicide. The corrected participation rate was 50%; 363 questionnaires were analysed. Overall 72% of doctors agreed with the possibility of rational suicide, 17% disagreed, and 11% were neutral. Doctors who identified themselves as being more religious were more likely to disagree. Some doctors who disagreed with legalisation of physician assisted suicide nevertheless agreed with the concept of rational suicide. Most senior doctors in England and Wales feel that rational suicide is possible. There was no association with specialty. Strong religious belief was associated with disagreement, although levels of agreement were still high in people reporting the strongest religious belief. Most doctors who were opposed to physician assisted suicide believed that rational suicide was possible, suggesting that some medical opposition is best explained by other factors such as concerns of assessment and protection of vulnerable patients.
Netter, Sarah
tensions experience by sharing platforms by looking at the case of mobile fashion reselling and swapping markets. The final paper combines the perspectives of different sharing economy stakeholders and outlines some of the micro and macro tensions arising in and influencing the organization of these multi...... and to provide a more nuanced understanding of the micro- and macro-level tensions that characterize the sharing economy. This thesis consists of four research papers, each using different literature, methodology, and data sets. The first paper investigates how the sharing economy is diffused and is ‘talked...... into existence’ by the communicative acts of a number of different actors. The second paper looks at how the reality of these narratives is actually experienced by the representatives of one type of sharing platform, i.e., fashion libraries. The third paper further expands the understanding of micro-level...
Netter, Sarah
Despite the growing interest on the part of proponents and opponents - ranging from business, civil society, media, to policy-makers alike - there is still limited knowledge about the working mechanisms of the sharing economy. The thesis is dedicated to explore this understudied phenomenon...... and to provide a more nuanced understanding of the micro- and macro-level tensions that characterize the sharing economy. This thesis consists of four research papers, each using different literature, methodology, and data sets. The first paper investigates how the sharing economy is diffused and is ‘talked......-level tensions experience by sharing platforms by looking at the case of mobile fashion reselling and swapping markets. The final paper combines the perspectives of different sharing economy stakeholders and outlines some of the micro and macro tensions arising in and influencing the organization of these multi...
Ghrelin and gastric acid secretion
Koji Yakabi; Junichi Kawashima; Shingo Kato
2008-01-01
Ghrelin, a novel growth hormone-releasing peptide, was originally isolated from rat and human stomach. Ghrelin has been known to increase the secretion of growth hormone (GH), food intake, and body weight gain when administered peripherally or centrally. Ghrelin is also known to stimulate the gastric motility and the secretion of gastric acid. In the previous studies, the action of ghrelin on acid secretion was shown to be as strong as that of histamine and gastrin in-vivo experiment. In the studies, the mechanism for the action of ghrelin was also investigated. It was shown that vagotomy completely inhibited the action of ghrelin on the secretion of gastric acid suggesting that vagal nerve is involved in the mechanism for the action of ghrelin on acid secretion. As famotidine did not inhibit ghrelin-in-duced acid secretion in the study by Masuda et al, they concluded that histamine was not involved in the action of ghrelin on acid secretion. However, we have shown that famotidine completely inhibited ghrelin-induced acid secretion and histidine decarboxylase (HDC) mRNA was increased in gastric mucosa by ghrelin injection which is inhibited by vagotomy Our results indicate that histamine is involved in the action of ghrelin on acid secretion. Furthermore synergistic action of gastrin and ghrelin on gastric add secretion was shown. Although gastrin has important roles in postprandial secretion of gastric acid, ghrelin may be related to acid secretion during fasting period or at night. However, further studies are needed to elucidate the physiological role of ghrelin in acid secretion.
Ghrelin and gastric acid secretion.
Yakabi, Koji; Kawashima, Junichi; Kato, Shingo
2008-11-07
Ghrelin, a novel growth hormone-releasing peptide, was originally isolated from rat and human stomach. Ghrelin has been known to increase the secretion of growth hormone (GH), food intake, and body weight gain when administered peripherally or centrally. Ghrelin is also known to stimulate the gastric motility and the secretion of gastric acid. In the previous studies, the action of ghrelin on acid secretion was shown to be as strong as that of histamine and gastrin in in-vivo experiment. In the studies, the mechanism for the action of ghrelin was also investigated. It was shown that vagotomy completely inhibited the action of ghrelin on the secretion of gastric acid suggesting that vagal nerve is involved in the mechanism for the action of ghrelin on acid secretion. As famotidine did not inhibit ghrelin-induced acid secretion in the study by Masuda et al, they concluded that histamine was not involved in the action of ghrelin on acid secretion. However, we have shown that famotidine completely inhibited ghrelin-induced acid secretion and histidine decarboxylase (HDC) mRNA was increased in gastric mucosa by ghrelin injection which is inhibited by vagotomy Our results indicate that histamine is involved in the action of ghrelin on acid secretion. Furthermore synergistic action of gastrin and ghrelin on gastric acid secretion was shown. Although gastrin has important roles in postprandial secretion of gastric acid, ghrelin may be related to acid secretion during fasting period or at night. However, further studies are needed to elucidate the physiological role of ghrelin in acid secretion.
Rational Verification in Iterated Electric Boolean Games
Youssouf Oualhadj
2016-07-01
Full Text Available Electric boolean games are compact representations of games where the players have qualitative objectives described by LTL formulae and have limited resources. We study the complexity of several decision problems related to the analysis of rationality in electric boolean games with LTL objectives. In particular, we report that the problem of deciding whether a profile is a Nash equilibrium in an iterated electric boolean game is no harder than in iterated boolean games without resource bounds. We show that it is a PSPACE-complete problem. As a corollary, we obtain that both rational elimination and rational construction of Nash equilibria by a supervising authority are PSPACE-complete problems.
COMPUTATION OF VECTOR VALUED BLENDING RATIONAL INTERPOLANTS
檀结庆
2003-01-01
As we know, Newton's interpolation polynomial is based on divided differ-ences which can be calculated recursively by the divided-difference scheme while Thiele'sinterpolating continued fractions are geared towards determining a rational functionwhich can also be calculated recursively by so-called inverse differences. In this paper,both Newton's interpolation polynomial and Thiele's interpolating continued fractionsare incorporated to yield a kind of bivariate vector valued blending rational interpolantsby means of the Samelson inverse. Blending differences are introduced to calculate theblending rational interpolants recursively, algorithm and matrix-valued case are dis-cussed and a numerical example is given to illustrate the efficiency of the algorithm.
Perturbing rational harmonic functions by poles
Sète, Olivier; Liesen, Jörg
2014-01-01
We study how adding certain poles to rational harmonic functions of the form $R(z)-\\bar{z}$, with $R(z)$ rational and of degree $d\\geq 2$, affects the number of zeros of the resulting functions. Our results are motivated by and generalize a construction of Rhie derived in the context of gravitational microlensing (ArXiv e-print 2003). Of particular interest is the construction and the behavior of rational functions $R(z)$ that are {\\em extremal} in the sense that $R(z)-\\bar{z}$ has the maximal possible number of $5(d-1)$ zeros.
Positivity Preserving Interpolation Using Rational Bicubic Spline
Samsul Ariffin Abdul Karim
2015-01-01
Full Text Available This paper discusses the positivity preserving interpolation for positive surfaces data by extending the C1 rational cubic spline interpolant of Karim and Kong to the bivariate cases. The partially blended rational bicubic spline has 12 parameters in the descriptions where 8 of them are free parameters. The sufficient conditions for the positivity are derived on every four boundary curves network on the rectangular patch. Numerical comparison with existing schemes also has been done in detail. Based on Root Mean Square Error (RMSE, our partially blended rational bicubic spline is on a par with the established methods.
Bounded rational choice behaviour: applications in transport
Jensen, Anders Fjendbo
2016-01-01
rational choice behaviour focuses on how the latter approach can be seriously taken into account within transport applications. As the editors discuss in the introduction, a true optimal choice can only be made if an individual has full and perfect information of all relevant attributes in his/her choice......Even though the theory of rational behaviour has been challenged for almost 100 years, the dominant approach within the field of transport has been based upon the assumptions of neoclassical economics that we live in a world of rational decision makers who always have perfect knowledge and aim...
Height Estimates for Equidimensional Dominant Rational Maps
Silverman, Joseph H
2009-01-01
Let F : W --> V be a dominant rational map between quasi-projective varieties of the same dimension. We give two proofs that h_V(F(P)) >> h_W(P) for all points P in a nonempty Zariski open subset of W. For dominant rational maps F : P^n --> P^n, we give a uniform estimate in which the implied constant depends only on n and the degree of F. As an application, we prove a specialization theorem for equidimensional dominant rational maps to semiabelian varieties, providing a complement to Habegger's recent theorem on unlikely intersections.
Chimpanzees share forbidden fruit.
Kimberley J Hockings
Full Text Available The sharing of wild plant foods is infrequent in chimpanzees, but in chimpanzee communities that engage in hunting, meat is frequently used as a 'social tool' for nurturing alliances and social bonds. Here we report the only recorded example of regular sharing of plant foods by unrelated, non-provisioned wild chimpanzees, and the contexts in which these sharing behaviours occur. From direct observations, adult chimpanzees at Bossou (Republic of Guinea, West Africa very rarely transferred wild plant foods. In contrast, they shared cultivated plant foods much more frequently (58 out of 59 food sharing events. Sharing primarily consists of adult males allowing reproductively cycling females to take food that they possess. We propose that hypotheses focussing on 'food-for-sex and -grooming' and 'showing-off' strategies plausibly account for observed sharing behaviours. A changing human-dominated landscape presents chimpanzees with fresh challenges, and our observations suggest that crop-raiding provides adult male chimpanzees at Bossou with highly desirable food commodities that may be traded for other currencies.
Elbæk, Mikael Karstensen
2010-01-01
Knowledge is one of the few commodities that don’t devalue when used. Actually knowledge grows when shared and the free online access to peer-reviewed scientific publications is a potent ingredient the process of sharing. The sharing of knowledge is facilitated by the Open Access Movement. However...... infrastructure for Open Access was launched in Ghent, Belgium. This project and initiative is facilitating the success of the Open Access Pilot in FP7 as presented earlier in this journal. In this brief article I will present some of the most interesting issues that were discussed during the first session...
Frederiksen, Linda; Nance, Heidi
2011-01-01
Written from a global perspective, this book reviews sharing of library resources on a global scale. With expanded discovery tools and massive digitization projects, the rich and extensive holdings of the world's libraries are more visible now than at any time in the past. Advanced communication and transmission technologies, along with improved international standards, present a means for the sharing of library resources around the globe. Despite these significant improvements, a number of challenges remain. Global Resource Sharing provides librarians and library managers with a comprehensive
Ganuza, Juan José; Jansen, Jos
2013-01-01
By using general information structures and precision criteria based on the dispersion of conditional expectations, we study how oligopolists’ information acquisition decisions may change the effects of information sharing on the consumer surplus. Sharing information about individual cost...... parameters gives the following trade-off in Cournot oligopoly. On the one hand, it decreases the expected consumer surplus for a given information precision, as the literature shows. On the other hand, information sharing increases the firms’ incentives to acquire information, and the consumer surplus...... increases in the precision of the firms’ information. Interestingly, the latter effect may dominate the former effect....
2008-01-01
China Ocean Shipping(Group)Co.(COSCO) employs an experimental strategy of making acquisitions through the purchase of B shares COSCO Pacific Ltd.and its affili- ated companies held 4.5 million shares of China International Marine Containers(Grouo)Co.Ltd.(CIMC) as of March 6. Four months ago,the board of direc- tors of COSCO Container Industries Ltd. (COSCO Container)decided to buy more B shares of CIMC through the securities mar- ket.COSCO Container is a shell company registered in the British Virgin Islands with a
Holomorphic Cartan geometries and rational curves
Biswas, Indranil
2010-01-01
We prove that any compact K\\"ahler manifold bearing a holomorphic Cartan geometry contains a rational curve just when the Cartan geometry is inherited from a holomorphic Cartan geometry on a lower dimensional compact K\\"ahler manifold.
Beyond rationality : Counterfactual thinking and behavior regulation
Epstude, Kai; Roese, Neal J.
2007-01-01
Counterfactual thinking may be described as disciplined realistic, and rational, but we move a step further to describe a theoretical perspective centering on behavior regulation. According to this perspective, counterfactual thinking primarily centers on coordination of ongoing behavior. In short,
Popper, Rationality and the Possibility of Social Science
Danny Frederick
2013-02-01
Full Text Available Social science employs teleological explanations which depend upon the rationality principle, according to which people exhibit instrumental rationality. Popper points out that people also exhibit critical rationality, the tendency to stand back from, and to question or criticise, their views. I explain how our critical rationality impugns the explanatory value of the rationality principle and thereby threatens the very possibility of social science. I discuss the relationship between instrumental and critical rationality and show how we can reconcile our critical rationality with the possibility of social science if we invoke Popper’s conception of limited rationality and his indeterminism.
RIC-7 promotes neuropeptide secretion.
Yingsong Hao
2012-01-01
Full Text Available Secretion of neurotransmitters and neuropeptides is mediated by exocytosis of distinct secretory organelles, synaptic vesicles (SVs and dense core vesicles (DCVs respectively. Relatively little is known about factors that differentially regulate SV and DCV secretion. Here we identify a novel protein RIC-7 that is required for neuropeptide secretion in Caenorhabditis elegans. The RIC-7 protein is expressed in all neurons and is localized to presynaptic terminals. Imaging, electrophysiology, and behavioral analysis of ric-7 mutants indicates that acetylcholine release occurs normally, while neuropeptide release is significantly decreased. These results suggest that RIC-7 promotes DCV-mediated secretion.
Salmonella-secreted Virulence Factors
Heffron, Fred; Niemann, George; Yoon, Hyunjin; Kidwai, Afshan S.; Brown, Roslyn N.; McDermott, Jason E.; Smith, Richard D.; Adkins, Joshua N.
2011-05-01
In this short review we discuss secreted virulence factors of Salmonella, which directly affect Salmonella interaction with its host. Salmonella secretes protein to subvert host defenses but also, as discussed, to reduce virulence thereby permitting the bacteria to persist longer and more successfully disperse. The type III secretion system (TTSS) is the best known and well studied of the mechanisms that enable secretion from the bacterial cytoplasm to the host cell cytoplasm. Other secretion systems include outer membrane vesicles, which are present in all Gram-negative bacteria examined to date, two-partner secretion, and type VI secretion will also be addressed. Excellent reviews of Salmonella secreted effectors have focused on themes such as actin rearrangements, vesicular trafficking, ubiquitination, and the activities of the virulence factors themselves. This short review is based on S. Typhimurium infection of mice because it is a model of typhoid like disease in humans. We have organized effectors in terms of events that happen during the infection cycle and how secreted effectors may be involved.
Is crime in Turkey economically rational?
2014-01-01
The study investigates whether crime in Turkey is governed by economic rationality. An economic model of rational behaviour claims that the propensity to commit criminal activities is negatively related to risk of deterrence. Potential presence of higher risk profiles for certain population segments is investigated. Panel data aggregated to sub-regional levels and observed annually for the years 2008 to 2010 are applied. Controls for endogeneity among criminal activity level and risk of deter...
Multinode rational operators for univariate interpolation
Dell'Accio, Francesco; Di Tommaso, Filomena; Hormann, Kai
2016-10-01
Birkhoff (or lacunary) interpolation is an extension of polynomial interpolation that appears when observation gives irregular information about function and its derivatives. A Birkhoff interpolation problem is not always solvable even in the appropriate polynomial or rational space. In this talk we split up the initial problem in subproblems having a unique polynomial solution and use multinode rational basis functions in order to obtain a global interpolant.
2-rational Cubic Spline Involving Tension Parameters
M Shrivastava; J Joseph
2000-08-01
In the present paper, 1-piecewise rational cubic spline function involving tension parameters is considered which produces a monotonic interpolant to a given monotonic data set. It is observed that under certain conditions the interpolant preserves the convexity property of the data set. The existence and uniqueness of a 2-rational cubic spline interpolant are established. The error analysis of the spline interpolant is also given.
Is crime in Turkey economically rational?
Lauridsen, Jørgen T.; Zeren, Fatma; Ari, Ayse
2014-01-01
The study investigates whether crime in Turkey is governed by economic rationality. An economic model of rational behaviour claims that the propensity to commit criminal activities is negatively related to risk of deterrence. Potential presence of higher risk profiles for certain population segments is investigated. Panel data aggregated to sub-regional levels and observed annually for the years 2008 to 2010 are applied. Controls for endogeneity among criminal activity level and risk of deter...
Rational emotive behaviour therapy: distinctive features
Dryden, Windy
2008-01-01
Rational emotive behaviour therapy (REBT) encourages the client to focus on their emotional problems in order to understand, challenge and change the irrational beliefs that underpin these problems. REBT can help clients to strengthen conviction in their alternative rational beliefs by acting in ways that are consistent with them and thus encourage a healthier outlook.\\ud \\ud This accessible and direct guide introduces the reader to REBT while indicating how it is different from other approac...
Artificial intelligence techniques for rational decision making
Marwala, Tshilidzi
2014-01-01
Develops insights into solving complex problems in engineering, biomedical sciences, social science and economics based on artificial intelligence. Some of the problems studied are in interstate conflict, credit scoring, breast cancer diagnosis, condition monitoring, wine testing, image processing and optical character recognition. The author discusses and applies the concept of flexibly-bounded rationality which prescribes that the bounds in Nobel Laureate Herbert Simon's bounded rationality theory are flexible due to advanced signal processing techniques, Moore's Law and artificial intellig
The neural basis of bounded rational behavior
Coricelli, Giorgio; Nagel, Rosemarie
2010-01-01
Bounded rational behaviour is commonly observed in experimental games and in real life situations. Neuroeconomics can help to understand the mental processing underlying bounded rationality and out-of-equilibrium behaviour. Here we report results from recent studies on the neural basis of limited steps of reasoning in a competitive setting —the beauty contest game. We use functional magnetic resonance imaging (fMRI) to study the neural correlates of human mental processes in strategic games. ...
Integral Models of Extremal Rational Elliptic Surfaces
Jarvis, Tyler J; Ricks, Jeremy R
2009-01-01
Miranda and Persson classified all extremal rational elliptic surfaces in characteristic zero. We show that each surface in Miranda and Persson's classification has an integral model with good reduction everywhere (except for those of type X_{11}(j), which is an exceptional case), and that every extremal rational elliptic surface over an algebraically closed field of characteristic p > 0 can be obtained by reducing one of these integral models mod p.
RATIONAL SOLUTIONS FOR DEVELOPMENT OF TELECOMMUNICATIONS NETWORKS
Sokolov, A.; Sokolov, N.
2014-01-01
The number of complicated problems has to be solved during modernization of the telecommunication networks. Some problems can be defined as a search for rational solutions instead of the traditional approach that consists in finding the cost function optimum. This new approach minimizes the risk that inevitably arises when elaborating a long term plan for the telecommunication networks development. The article discusses the proposed methodological approach of finding rational solutions. Probl...
Rational emotive behavior therapy: disputing irrational philosophies.
Sacks, Susan Bendersky
2004-05-01
This article provides an overview of the concepts and techniques of rational emotive behavior therapy to distinguish it from cognitive-behavioral therapy. Rational emotive behavior therapy proposes that psychological disturbance is largely created and maintained through irrational philosophies consisting of internal absolutistic demands. This therapy strives to produce sustained and profound cognitive, emotive, and behavioral change through active, vigorous disputation of underlying irrational philosophies.
Simple Equational Specifications of Rational Arithmetic
Lawrence S. Moss
2001-12-01
Full Text Available We exhibit an initial specification of the rational numbers equipped with addition, subtraction, multiplication, greatest integer function, and absolute value. Our specification uses only the sort of rational numbers. It uses one hidden function; that function is unary. But it does not use an error constant, or extra (hidden sorts, or conditional equations. All of our work is elementary and self-contained.
Municipal management cooperation : managing multiple rationalities
Holmberg, Leif
2010-01-01
Multiple rationality organizations are characterized by the simultaneously incorporation of different kinds of logic and control systems. They have to provide not only for efficiency but also to comply with e.g. ideal of fairness, sportsmanship, equal rights, and aesthetic values. Elite sport clubs, theatres, and several municipality activities are examples of organizations that have to cope with multiple rationalities. These organizations are often governed through a combination of politica...
Intergroup conflict and rational decision making.
Vicente Martínez-Tur
Full Text Available The literature has been relatively silent about post-conflict processes. However, understanding the way humans deal with post-conflict situations is a challenge in our societies. With this in mind, we focus the present study on the rationality of cooperative decision making after an intergroup conflict, i.e., the extent to which groups take advantage of post-conflict situations to obtain benefits from collaborating with the other group involved in the conflict. Based on dual-process theories of thinking and affect heuristic, we propose that intergroup conflict hinders the rationality of cooperative decision making. We also hypothesize that this rationality improves when groups are involved in an in-group deliberative discussion. Results of a laboratory experiment support the idea that intergroup conflict -associated with indicators of the activation of negative feelings (negative affect state and heart rate- has a negative effect on the aforementioned rationality over time and on both group and individual decision making. Although intergroup conflict leads to sub-optimal decision making, rationality improves when groups and individuals subjected to intergroup conflict make decisions after an in-group deliberative discussion. Additionally, the increased rationality of the group decision making after the deliberative discussion is transferred to subsequent individual decision making.
Intergroup conflict and rational decision making.
Martínez-Tur, Vicente; Peñarroja, Vicente; Serrano, Miguel A; Hidalgo, Vanesa; Moliner, Carolina; Salvador, Alicia; Alacreu-Crespo, Adrián; Gracia, Esther; Molina, Agustín
2014-01-01
The literature has been relatively silent about post-conflict processes. However, understanding the way humans deal with post-conflict situations is a challenge in our societies. With this in mind, we focus the present study on the rationality of cooperative decision making after an intergroup conflict, i.e., the extent to which groups take advantage of post-conflict situations to obtain benefits from collaborating with the other group involved in the conflict. Based on dual-process theories of thinking and affect heuristic, we propose that intergroup conflict hinders the rationality of cooperative decision making. We also hypothesize that this rationality improves when groups are involved in an in-group deliberative discussion. Results of a laboratory experiment support the idea that intergroup conflict -associated with indicators of the activation of negative feelings (negative affect state and heart rate)- has a negative effect on the aforementioned rationality over time and on both group and individual decision making. Although intergroup conflict leads to sub-optimal decision making, rationality improves when groups and individuals subjected to intergroup conflict make decisions after an in-group deliberative discussion. Additionally, the increased rationality of the group decision making after the deliberative discussion is transferred to subsequent individual decision making.
Proposed standby gasoline rationing plan: public comments
1978-12-01
Under the proposed plan, DOE would allocate ration rights (rights to purchase gasoline) to owners of registered vehicles. All vehicles in a given class would receive the same entitlement. Essential services would receive supplemental allotments of ration rights as pririty firms. Once every 3 months, ration checks would be mailed out to all vehicle registrants, allotting them a certain amount of ration rights. These checks would then be cashed at Coupon Issuance Points, where the bearer would receive ration coupons to be used at gasoline stations. Large users of gasoline could deposit their allotment checks in accounts at ration banks. Coupons or checks would be freely exchangeable in a white market. A certain percentage of the gasoline supply would be set aside in reserve for use in national emergencies. When the plan was published in the Federal Register, public comments were requested. DOE also solicited comments from private citizens, public interest groups, business and industry, state and local governments. A total of 1126 responses were reveived and these are analyzed in this paper. The second part of the report describes how the comments were classified, and gives a statistical breakdown of the major responses. The last section is a discussion and analysis of theissue raised by commenting agencies, firms, associations, and individuals. (MCW)
The concept of negotiation in shared decision making.
Sandman, Lars
2009-09-01
In central definitions of shared decision-making within medical consultations we find the concept of negotiation used to describe the interaction between patient and professional in case of conflict. It has been noted that the concept of negotiation is far from clear in this context and in other contexts it is used both in terms of rational deliberation and bargaining. The articles explores whether rational deliberation or bargaining accurately describes the negotiation in shared decision-making and finds that it fails to do so on both descriptive and normative grounds. At the end some notes on further analysis is given and it is suggested that the interaction is more accurately described in terms of an internal balancing of values like patient best interest, patient autonomy and patient adherence by the professional that is accepted by the patient.
... the rest of your life Having major surgery Getting genetic or cancer screening tests Talking together about your options helps your provider know how you feel and what you value. How Shared Decision Making Works When facing a decision, your ...
Bregnbæk, Susanne
2011-01-01
This article is based on anthropological fieldwork undertaken at two elite universities in Beijing. It addresses the paradoxical situation of the many instances of suicide among Chinese elite university students in Beijing, which constitute a public secret. The pressure of education weighs heavily...... on the shoulders of China’s only child in each family, known as the generation of little emperors and little empresses. Since the 1980s, the suzhi jiaoyu reforms (education for quality) have involved various attempts to reduce the pressure of education. However, simultaneously the aim is to increase...... the competitiveness of individuals. Drawing on existential and phenomenological thought, I suggest that the discourse seems to objectify and quantify a concern for well-being, rather than recognising its intersubjective character. Finally, I argue that the suicides are controversial since they are seen as a form...
Maximilien Brice
2002-01-01
The library is launching a 'sharing resources@CERN' campaign, aiming to increase the library's utility by including the thousands of books bought by individual groups at CERN. This will improve sharing of information among CERN staff and users. Photo 01: L. to r. Eduardo Aldaz, from the PS division, Corrado Pettenati, Head Librarian, and Isabel Bejar, from the ST division, read their divisional copies of the same book.
2008-01-01
A huge number of restricted shares were made tradable in March in the mainland stock market,testing the capability of the fragile capital market Ping An of China has been made the main scapegoat of this year s stock market plunge.A month after its refinancing plan announcement- equivalent to recreating a new Ping An- its 3.12 billion restricted shares were made tradable on March 3,accounting for almost
Performing the sharing economy.
Richardson, L
2015-01-01
The sharing economy converges around activities facilitated through digital platforms that enable peer-to-peer access to goods and services. It constitutes an apparent paradox, framed as both part of the capitalist economy and as an alternative. This duplicity necessitates focusing on the performances of the sharing economy: how it simultaneously constructs diverse economic activities whilst also inviting the deconstruction of ongoing practices of dominance. Such performances hold open the qu...
Pro-environmental behavior: rational choice meets moral motivation.
Turaga, Rama Mohana R; Howarth, Richard B; Borsuk, Mark E
2010-01-01
The determinants of individual behaviors that provide shared environmental benefits are a longstanding theme in social science research. Alternative behavioral models yield markedly different predictions and policy recommendations. This paper reviews and compares the literatures from two disciplines that appear to be moving toward a degree of convergence. In social psychology, moral theories of pro-environmental behavior have focused on the influence of personal moral norms while recognizing that external factors, such as costs and incentives, ultimately limit the strength of the norm-behavior relationship. Rational choice models, such as the theory of planned behavior in social psychology and the theories of voluntary provision of public goods in economics, have sought to incorporate the effects of personal norms and to measure their importance in explaining behaviors, such as recycling and the demand for green products. This paper explores the relationship between these approaches and their implications for the theory and practice of ecological economics.
Interactions in multiagent systems fairness, social optimality and individual rationality
Hao, Jianye
2016-01-01
This book mainly aims at solving the problems in both cooperative and competitive multi-agent systems (MASs), exploring aspects such as how agents can effectively learn to achieve the shared optimal solution based on their local information and how they can learn to increase their individual utility by exploiting the weakness of their opponents. The book describes fundamental and advanced techniques of how multi-agent systems can be engineered towards the goal of ensuring fairness, social optimality, and individual rationality; a wide range of further relevant topics are also covered both theoretically and experimentally. The book will be beneficial to researchers in the fields of multi-agent systems, game theory and artificial intelligence in general, as well as practitioners developing practical multi-agent systems.
Neural basis of quasi-rational decision making.
Lee, Daeyeol
2006-04-01
Standard economic theories conceive homo economicus as a rational decision maker capable of maximizing utility. In reality, however, people tend to approximate optimal decision-making strategies through a collection of heuristic routines. Some of these routines are driven by emotional processes, and others are adjusted iteratively through experience. In addition, routines specialized for social decision making, such as inference about the mental states of other decision makers, might share their origins and neural mechanisms with the ability to simulate or imagine outcomes expected from alternative actions that an individual can take. A recent surge of collaborations across economics, psychology and neuroscience has provided new insights into how such multiple elements of decision making interact in the brain.
Regulating the sharing economy
Kristofer Erickson
2016-06-01
Full Text Available In this introductory essay, we explore definitions of the ‘sharing economy’, a concept indicating both social (relational, communitarian and economic (allocative, profit-seeking aspects which appear to be in tension. We suggest combining the social and economic logics of the sharing economy to focus on the central features of network enabled, aggregated membership in a pool of offers and demands (for goods, services, creative expressions. This definition of the sharing economy distinguishes it from other related peer-to-peer and collaborative forms of production. Understanding the social and economic motivations for and implications of participating in the sharing economy is important to its regulation. Each of the papers in this special issue contributes to knowledge by linking the social and economic aspects of sharing economy practices to regulatory norms and mechanisms. We conclude this essay by suggesting future research to further clarify and render intelligible the sharing economy, not as a contradiction in terms but as an empirically observable realm of socio-economic activity.
Information partnerships--shared data, shared scale.
Konsynski, B R; McFarlan, F W
1990-01-01
How can one company gain access to another's resources or customers without merging ownership, management, or plotting a takeover? The answer is found in new information partnerships, enabling diverse companies to develop strategic coalitions through the sharing of data. The key to cooperation is a quantum improvement in the hardware and software supporting relational databases: new computer speeds, cheaper mass-storage devices, the proliferation of fiber-optic networks, and networking architectures. Information partnerships mean that companies can distribute the technological and financial exposure that comes with huge investments. For the customer's part, partnerships inevitably lead to greater simplification on the desktop and more common standards around which vendors have to compete. The most common types of partnership are: joint marketing partnerships, such as American Airline's award of frequent flyer miles to customers who use Citibank's credit card; intraindustry partnerships, such as the insurance value-added network service (which links insurance and casualty companies to independent agents); customer-supplier partnerships, such as Baxter Healthcare's electronic channel to hospitals for medical and other equipment; and IT vendor-driven partnerships, exemplified by ESAB (a European welding supplies and equipment company), whose expansion strategy was premised on a technology platform offered by an IT vendor. Partnerships that succeed have shared vision at the top, reciprocal skills in information technology, concrete plans for an early success, persistence in the development of usable information for all partners, coordination on business policy, and a new and imaginative business architecture.
On the price of different classes of shares
O. CASTELLINO
2013-12-01
Full Text Available Neither the opponents nor the supporters of the efficiency proposition investigate whether stock prices may rationally reflect further elements in addition to future dividends. The experience of several countries, however, shows that market prices of different types of shares may diverge, and sometimes considerably so. Indeed, economic theory does not seem to have devoted sufficient attention to the magnitude and determinants of different valuations. The present paper analyses this issue in two steps. First, a stable situation is considered, where the distribution of shares between “majority” and “minority” shareholders is fixed. Second, and unstable situation where the possibility of changes in the distribution of shares is explicitly considered. In both cases, two classes of shares are considered, one with full voting rights and another with no voting rights at all.
A discussion of theoretical and practical rationality
Wahlstroem, B. [Technical Research Centre of Finland, Espoo (Finland). VTT Automation
1999-12-01
Theoretical rationality as defined in Expected Utility Theory and amended with other considerations gives a good basis for decision making. One should however always keep in mind that practical rationality often is far more complicated. People use their everyday experience when placed before new problems and this may lead to apparently irrational choices which on a closer scrutiny may be completely rational. Theories in human decision making unfortunately becomes untestable, firstly because a theory taking all considerations into account would be to complex to be practical and secondly because the data needed to test the theory cannot be collected. The benefit of EUT is that it is simple and straightforward as compared with competing theories. In the natural sciences rationality is often seen simply as a problem of optimisation. This view is practical, but it has to include also psychological and sociological considerations. The apparent controversy between natural and behavioural sciences could at least in principle be resolved by a better understanding of the complexity of human rationality. The human mind does not work in isolation, but it is adapted to a social community and a continuously changing environment. Understanding all components of human rationality is a challenge which cannot be solved on a short term basis. An important part of human rationality is connected to the intricate balance between individual and societal utility. The human mind has over thousands of years learnt to resolve that balance, but in the modern society there are decisions which may not be solvable with an intuitive approach and a strategy of trial and error. For these decisions more solid theories of rationality will be needed. EUT can in spite of its dismerits be used as the backbone for such a theory, but it has to be extended with better explanations of both individual and social rationality. If this understanding of the practical aspects of human rationality can be reached
Ranajee
2016-08-01
Full Text Available Price momentum is a phenomenon which is widely reported in different markets, different time frames and in almost all asset classes. Initially reported by Jegadeesh and Titman [1] it is found to be persistent across asset classes, markets and different geographies. As per rational theories of finance an investor is compensated for the level of risk taken in the market. Market knows the best notion doesn’t agree with a notion of positive alpha. Even if a trading strategy earns a positive alpha in short run, it should not be consistent in long run. But momentum is an exception in this respect. Macroeconomists say that stock market is nothing but a lagged indicator of the macroeconomic conditions and growth prospects available in a country, so macroeconomic factors should explain any of the excess return phenomenon. Similarly market state is a factor which is systematic or a risk of non-diversifiable nature and hence it may affect the momentum return. Again growth factors of the individual companies with access to prudent management and non-substitutable resources provide sustained competitive advantage and can result in sustained stock market performance by a company. Similarly, changing choices and preferences of customers and investors can change the performance of stocks in negative manner also. What differentiates all these factors is the extent of influence and the time horizon for getting the effect on stock returns.
Review of novel aspects of the regulation of ghrelin secretion.
Al Massadi, Omar; Lear, Pamela V; Muller, Timo D; Lopez, Miguel; Dieguez, Carlos; Tschop, Matthias H; Nogueiras, Ruben
2014-01-01
The role of ghrelin in regulating metabolism and energy balance has been a subject of intense focus ever since its discovery. Ghrelin regulates energy balance in the short term by induction of appetite and in the longer term by increasing body weight and adiposity. It is the only known peripheral orexigenic hormone and one of the most potent endogenous orexigenic factors discovered to date. However, whilst extensively studied, the mechanism of ghrelin secretion is not well understood. A better understanding of the pathways controlling ghrelin secretion could be useful in the development of new therapeutic approaches to appetite-related disorders. Here, we discuss current knowledge of the processes that control ghrelin secretion, focusing on neural, chemical and hormonal stimuli. In addition, we share our view on the potential of targeting ghrelin for the treatment of eating disorders such as obesity, anorexia nervosa and cachexia.
Direct Use of Secret Key in Quantum Cryptography
Yuen, H P
2006-01-01
For single-photon quantum key generation between two users, it is shown that for collective attacks the use of a shared secret key extended via a pseudo-random number generator may simultaneously enhance the security and efficiency of the cryptosystem. This effect arises from the intrinsic performance difference between quantum detectors with versus without knowledge of the key, a purely quantum effect and a new principle for key generation. No intrusion level estimation is needed and the method is directly applicable to realistic systems involving multi-photon sources, losses, noises, and finite-sequence statistical fluctuations. It is suggested that such use of a secret key be routinely incorporated in a quantum key generation system. The use of a secret key in quantum direct encryption is also indicated.
Yohimbine increases human salivary secretion.
Chatelut, E; Rispail, Y; Berlan, M; Montastruc, J L
1989-01-01
The effect of oral yohimbine (14 mg) on salivary secretion was evaluated in healthy volunteers. Yohimbine significantly increased salivary secretion when compared with placebo. This effect was significant from 60 min until 180 min after administration under our experimental conditions. Yohimbine (or alpha 2-adrenoceptor blocking agents) could have a potential interest in the treatment of dry mouths. PMID:2789932
Lee, Hanjing; Yap, Yan Lin; Low, Jeffrey Jen Hui
2017-01-01
Defects involving specialised areas with characteristic anatomical features, such as the nipple, upper eyelid, and lip, benefit greatly from the use of sharing procedures. The vulva, a complex 3-dimensional structure, can also be reconstructed through a sharing procedure drawing upon the contralateral vulva. In this report, we present the interesting case of a patient with chronic, massive, localised lymphedema of her left labia majora that was resected in 2011. Five years later, she presented with squamous cell carcinoma over the left vulva region, which is rarely associated with chronic lymphedema. To the best of our knowledge, our management of the radical vulvectomy defect with a labia majora sharing procedure is novel and has not been previously described. The labia major flap presented in this report is a shared flap; that is, a transposition flap based on the dorsal clitoral artery, which has consistent vascular anatomy, making this flap durable and reliable. This procedure epitomises the principle of replacing like with like, does not interfere with leg movement or patient positioning, has minimal donor site morbidity, and preserves other locoregional flap options for future reconstruction. One limitation is the need for a lax contralateral vulva. This labia majora sharing procedure is a viable option in carefully selected patients. PMID:28194353
On computing closed forms for summations. [polynomials and rational functions
Moenck, R.
1977-01-01
The problem of finding closed forms for a summation involving polynomials and rational functions is considered. A method closely related to Hermite's method for integration of rational functions derived. The method expresses the sum of a rational function as a rational function part and a transcendental part involving derivatives of the gamma function.
Using Rational-Emotive Therapy to Prevent Classroom Problems.
Webber, Jo; Coleman, Maggie
1988-01-01
Teachers are encouraged to utilize rational-emotive therapy to prevent and deal with classroom behavior problems. Rational-emotive therapy is defined, the ABC model of rational thinking briefly explained, types of irrational thinking identified, and suggestions for becoming a rational thinker are offered. Classroom examples are given. (DB)
Economic Rationality in the Ultimatum Game
Jan Fiala
2017-03-01
Full Text Available Rigorous application of experimental methodology to the interdisciplinary research of economic decision making is the main purpose of our work. In this paper, we introduce the main decisionmaking theories and outline economic rationality. We explain why we find it useful to discriminate between the “irrational” and “non-rational” components of decision making. We offer an oriented interdisciplinary point of view on economic rationality. In the applied section, we describe the main features of the Ultimatum game and summarize the up-to-date theories explaining the non-rational course of the game. We discuss in detail the reported relations between the nominal value of the stakes and the distribution of the offers and responses. We introduce the blinded, randomized Ultimatum game experiment that we conducted in our laboratory. We stress the importance of anonymity of the study subjects and the difference in salience of a factual reward against a hypothetical reward. We present the results of our study, showing that a duly chosen non-monetary reward, directly inconvertible into money, leads to a different offer distribution in the Ultimatum game without the necessity to invest excessive sums of money in the rewards. We compare our results to research published by other authors. According to our theory, the rational, non-rational and irrational components contribute to the decision making in Ultimatum differently depending on the different reward stakes.
Rational drug design applied to myeloperoxidase inhibition.
Van Antwerpen, P; Zouaoui Boudjeltia, K
2015-06-01
Rational drug design is a general approach using protein-structure technique in which the discovery of a ligand can be driven either by chance, screening, or rational theory. Myeloperoxidase (MPO) was rapidly identified as a therapeutical target because of its involvement in chronic inflammatory syndromes. In this context, the research of MPO inhibitors was intensified and development of new chemical entities was rationally driven by the research of ligands that enter into the MPO catalytic pocket. Actually, as soon as crystallography data of MPO have become available and its structure was virtually designed, the rational drug design has been applied to this peroxidase. Pharmaceutical industries and academic laboratories apply rational drug design on MPO by either optimizing known inhibitors or searching new molecules by high-throughput virtual screening. By these ways, they were able to find efficient MPO inhibitors and understand their interactions with the enzyme. During this quest of MPO inhibition, it appears that Glu268 is a crucial residue in order to optimize ligand-target interaction. This amino acid should be carefully considered by medicinal chemist when they design inhibitors interfering with MPO activity.
Multiple Ca2+ sensors in secretion
Walter, Alexander M; Groffen, Alexander J; Sørensen, Jakob Balslev;
2011-01-01
Regulated neurotransmitter secretion depends on Ca(2+) sensors, C2 domain proteins that associate with phospholipids and soluble N-ethylmaleimide-sensitive fusion attachment protein receptor (SNARE) complexes to trigger release upon Ca(2+) binding. Ca(2+) sensors are thought to prevent spontaneous...... fusion at rest (clamping) and to promote fusion upon Ca(2+) activation. At least eight, often coexpressed, Ca(2+) sensors have been identified in mammals. Accumulating evidence suggests that multiple Ca(2+) sensors interact, rather than work autonomously, to produce the complex secretory response...... observed in neurons and secretory cells. In this review, we present several working models to describe how different sensors might be arranged to mediate synchronous, asynchronous and spontaneous neurotransmitter release. We discuss the scenario that different Ca(2+) sensors typically act on one shared...
Secrets of mlearning failures: confronting reality
Thomas Cochrane
2012-08-01
Full Text Available Having implemented and evaluated over 35 mlearning projects in a variety of contexts in higher education over the past 6 years the researcher is ready to share the untold secret: not all mlearning projects succeed! This article critiques three of the researcher's mlearning projects that can be classed as “failures” and compares them to successful projects to draw out critical implications for mlearning project design and implementation to avoid common pitfalls leading to potential project failure. This article uses the researcher's six critical success factors identified across the 35 mlearning projects to evaluate these three projects, and concludes that projects resulting in “no significant difference” in pedagogical outcomes are the result of attempts to shoehorn old pedagogies into new technologies. Lecturer professional development and sustained collaborative support are critical to fostering new pedagogies utilising the unique affordances of mobile devices.
Pheochromocytomas and secreting paragangliomas
Gimenez-Roqueplo Anne-Paule
2006-12-01
Full Text Available Abstract Catecholamine-producing tumors may arise in the adrenal medulla (pheochromocytomas or in extraadrenal chromaffin cells (secreting paragangliomas. Their prevalence is about 0.1% in patients with hypertension and 4% in patients with a fortuitously discovered adrenal mass. An increase in the production of catecholamines causes symptoms (mainly headaches, palpitations and excess sweating and signs (mainly hypertension, weight loss and diabetes reflecting the effects of epinephrine and norepinephrine on α- and β-adrenergic receptors. Catecholamine-producing tumors mimic paroxysmal conditions with hypertension and/or cardiac rhythm disorders, including panic attacks, in which sympathetic activation linked to anxiety reproduces the same signs and symptoms. These tumors may be sporadic or part of any of several genetic diseases: familial pheochromocytoma-paraganglioma syndromes, multiple endocrine neoplasia type 2, neurofibromatosis 1 and von Hippel-Lindau disease. Familial cases are diagnosed earlier and are more frequently bilateral and recurring than sporadic cases. The most specific and sensitive diagnostic test for the tumor is the determination of plasma or urinary metanephrines. The tumor can be located by computed tomography, magnetic resonance imaging and metaiodobenzylguanidine scintigraphy. Treatment requires resection of the tumor, generally by laparoscopic surgery. About 10% of tumors are malignant either at first operation or during follow-up, malignancy being diagnosed by the presence of lymph node, visceral or bone metastases. Recurrences and malignancy are more frequent in cases with large or extraadrenal tumors. Patients, especially those with familial or extraadrenal tumors, should be followed-up indefinitely.
Bassily, Raef
2010-01-01
In this paper, we introduce two new achievable schemes for the fading multiple access wiretap channel (MAC-WT). In the model that we consider, we assume that perfect knowledge of the state of all channels is available at all the nodes in a causal fashion. Our schemes use this knowledge together with the time varying nature of the channel model to align the interference from different users at the eavesdropper perfectly in a one-dimensional space while creating a higher dimensionality space for the interfering signals at the legitimate receiver hence allowing for better chance of recovery. While we achieve this alignment through signal scaling at the transmitters in our first scheme (scaling based alignment (SBA)), we let nature provide this alignment through the ergodicity of the channel coefficients in the second scheme (ergodic secret alignment (ESA)). For each scheme, we obtain the resulting achievable secrecy rate region. We show that the secrecy rates achieved by both schemes scale with SNR as 1/2log(SNR...
Montero Ruiz, E
2016-01-01
Surgical departments have increasing difficulties in caring for their hospitalised patients due to the patients' advanced age and comorbidity, the growing specialisation in medical training and the strong political-healthcare pressure that a healthcare organisation places on them, where surgical acts take precedence over other activities. The pressure exerted by these departments on the medical area and the deficient response by the interconsultation system have led to the development of a different healthcare organisation model: Shared care, which includes perioperative medicine. In this model, 2 different specialists share the responsibility and authority in caring for hospitalised surgical patients. Internal Medicine is the most appropriate specialty for shared care. Internists who exercise this responsibility should have certain characteristics and must overcome a number of concerns from the surgeon and anaesthesiologist. Copyright © 2015 Elsevier España, S.L.U. y Sociedad Española de Medicina Interna (SEMI). All rights reserved.
Toga, Arthur W; Dinov, Ivo D
The promise of Big Biomedical Data may be offset by the enormous challenges in handling, analyzing, and sharing it. In this paper, we provide a framework for developing practical and reasonable data sharing policies that incorporate the sociological, financial, technical and scientific requirements of a sustainable Big Data dependent scientific community. Many biomedical and healthcare studies may be significantly impacted by using large, heterogeneous and incongruent datasets; however there are significant technical, social, regulatory, and institutional barriers that need to be overcome to ensure the power of Big Data overcomes these detrimental factors. Pragmatic policies that demand extensive sharing of data, promotion of data fusion, provenance, interoperability and balance security and protection of personal information are critical for the long term impact of translational Big Data analytics.
Annika Osswald
Full Text Available Health-promoting effects have been attributed to a number of Bifidobacterium sp. strains. These effects as well as the ability to colonise the host depend on secreted proteins. Moreover, rational design of protein secretion systems bears the potential for the generation of novel probiotic bifidobacteria with improved health-promoting or therapeutic properties. To date, there is only very limited data on secretion signals of bifidobacteria available. Using in silico analysis, we demonstrate that all bifidobacteria encode the major components of Sec-dependent secretion machineries but only B. longum strains harbour Tat protein translocation systems. A reporter plasmid for secretion signals in bifidobacteria was established by fusing the coding sequence of the signal peptide of a sialidase of Bifidobacterium bifidum S17 to the phytase gene appA of E. coli. The recombinant strain showed increased phytase activity in spent culture supernatants and reduced phytase levels in crude extracts compared to the control indicating efficient phytase secretion. The reporter plasmid was used to screen seven predicted signal peptides in B. bifidum S17 and B. longum E18. The tested signal peptides differed substantially in their efficacy to mediate protein secretion in different host strains. An efficient signal peptide was used for expression and secretion of a therapeutically relevant protein in B. bifidum S17. Expression of a secreted cytosine deaminase led to a 100-fold reduced sensitivity of B. bifidum S17 to 5-fluorocytosine compared to the non-secreted cytosine deaminase suggesting efficient conversion of 5-fluorocytosine to the cytotoxic cancer drug 5-fluorouracil by cytosine deaminase occurred outside the bacterial cell. Selection of appropriate signal peptides for defined protein secretion might improve therapeutic efficacy as well as probiotic properties of bifidobacteria.
Oligopolistic Banks, Bounded Rationality, and the Credit Cycle
Tobias F. Rötheli
2012-01-01
Full Text Available This paper studies how boundedly rational default expectations affect the credit cycle. I propose a simple model of oligopolistic bank competition which serves to compare situations with just a portion of boundedly rational banks to situations where either all banks are rational or all banks are boundedly rational. When all banks are boundedly rational, the credit cycle is most amplified relative to the situation where all banks are rational. However, the amplifying effect of bounded rationality on the side of banks largely remains even when only a portion of banks are boundedly rational. Hence, the interest rate decisions of a minority of boundedly rational banks induce the more rational competitors to aggravate the credit cycle.
He, Jing; Ravn, Susanne
2017-01-01
to the highly specialized field of elite sports dance, we aim at exploring the way in which reciprocity unfolds in intensive deliberate practices of movement. In our analysis, we specifically argue that the ongoing dynamics of two separate flows of movement constitute a shared experience of dancing together....... In this sense, moving together, in sports dance, is a practical way of understanding each other. In agreement with Zahavi, our analysis emphasizes the bi-directed nature of sharing. However, at the same time, we contribute to Zahavi’s ongoing endeavour as the special case of sports dance reveals how reciprocity...
Staunstrup, Jørgen; Orth Gaarn-Larsen, Carsten
A mission shared by stakeholders, management and employees is a prerequisite for an engaging dialog about the many and substantial changes and challenges currently facing universities. Too often this essen-tial dialog reveals mistrust and misunderstandings about the role and outcome of the univer......A mission shared by stakeholders, management and employees is a prerequisite for an engaging dialog about the many and substantial changes and challenges currently facing universities. Too often this essen-tial dialog reveals mistrust and misunderstandings about the role and outcome...
ZHANG Wen-hua; PANG Xue-cheng
2006-01-01
This paper investigates the relationship between the normality and the shared values for a meromorphic function on the unit disc △.Based on Marty's normality criterion and through a detailed analysis of the meromorphic functions,it is shown that if for every f∈F,f and f(k) share a and b on △ and the zeros of f(z)-a are of multiplicity k≥3,then F is normal on △,where F is a family of meromorphic functions on the unit disc △,and a and b are distinct values.
Changing Conspiracy Beliefs through Rationality and Ridiculing
Gábor Orosz
2016-10-01
Full Text Available Conspiracy theory (CT beliefs can be harmful. How is it possible to reduce them effectively? Three reduction strategies were tested in an online experiment using general and well-known CT beliefs on a comprehensive randomly assigned Hungarian sample (N = 813: exposing rational counter CT arguments, ridiculing those who hold CT beliefs, and empathizing with the targets of CT beliefs. Several relevant individual differences were measured. Rational and ridiculing arguments were effective in reducing CT, whereas empathizing with the targets of CTs had no effect. Individual differences played no role in CT reduction, but the perceived intelligence and competence of the individual who conveyed the CT belief-reduction information contributed to the success of the CT belief reduction. Rational arguments targeting the link between the object of belief and its characteristics appear to be an effective tool in fighting conspiracy theory beliefs.
Decision Making: Between Rationality and Reality
Marko Polič
2009-12-01
Full Text Available Almost by definition decision-making is typical human activity, and therefore important psychological subject. The starting point of its classical conception within psychology could be traced back to economy and mathematic, with ideas of human as rational economic being, and conceptualising decision making as choice between two or more alternatives, and as such being a separate event in space and time. Already in fifties Herbert Simon challenged such a view with his concept of bounded rationality, emerging from the joint effect of internal limitations of the human mind, and the structure of external environments in which the mind operates. During the last decades with the shift to the real word situations where decisions are embedded in larger tasks, becoming so part of the study of action, the lost rational human appeared again as efficient creature in the complex environment. Gigerenzer showed how heuristics help in this process.
Rational speculative bubbles: A critical view
Radonjić Ognjen
2007-01-01
Full Text Available According to the theory of rational bubbles, the bubble is present whenever asset prices progressively diverge from their fundamental value, which occurs because agents expect that asset prices will continue to grow exponentially (self-fulfilling prophecies far in the future and consistently, which promises the realization of ever larger capital gains. In our opinion, the basic shortcoming of this theory refers to the assumption that all market agents are perfectly informed and rational and, accordingly, form homogeneous expectations. The model does not explain decision-making processes or expectation formation, nor does it detect potential psychological and institutional factors that might significantly influence decision making processes and market participants’ reactions to news. Since assumptions of the model critically determine its validity, we conclude that comprehensiveness of the rational bubble model is, to put it mildly, limited.
Direct Extraction of One Loop Rational Terms
Badger, S D
2009-01-01
We present a method for the direct extraction of rational contributions to one-loop scattering amplitudes, missed by standard four-dimensional unitarity techniques. Working in D=4-2*epsilon dimensions, we interpret the dependence on the additional dimensions as equivalent to introducing an internal mass. We combine this with the use of generalised unitarity to write the loop amplitudes in terms of products of massive tree amplitudes. We find that the rational terms in 4-2*epsilon dimensions can be determined from quadruple, triple and double cuts without the need for independent pentagon contributions using a massive integral basis. The additional mass-dependent integral coefficients may then be extracted analytically or numerically using discrete Fourier projections. We check the method by computing the rational parts of all gluon helicity amplitudes with up to six external legs.
Helicobacter pylori in lacrimal secretions.
Batioglu-Karaaltin, Aysegul; Saatci, Ozlem; Akpinar, Meltem; Celik, Melih Ozgür; Develioglu, Omer; Yigit, Ozgur; Külekçi, Mehmet; Akarsubaşı, Alper Tunga
2016-03-01
The aim of this study was to investigate the presence of Helicobacter pylori in human lacrimal and nasal secretions. Eighty patients with complaints of dyspepsia who had undergone endoscopies and gastric antrum biopsies were included in the study. A total of five specimens, including 2 lacrimal secretion samples, 2 nasal mucosal swab samples, and 1 gastric antrum biopsy, were collected from each patient and investigated with polymerase chain reaction (PCR) methods consisting of the urease enzyme coding gene GlmM (UreC) and the H pylori-specific 16S rRNA coding gene. The Reflux Symptom Index and ophthalmologic complaints of the patients were recorded. The detected positivity rates of the H pylori 16S rRNA coding gene in gastric biopsies and nasal mucous and lacrimal secretions were 55, 11.2, and 20%, respectively. The patients were grouped as gastric-antrum-biopsy-negative (Group I [n = 36]) and -positive (Group II [n = 44). In Group II, H pylori positivity in the lacrimal and nasal mucous secretions was 36.3 and 18%, respectively. A comparison between the groups in terms of H pylori presence in nasal mucous and lacrimal secretions yielded statistically significant differences (p = 0.0001, p = 0.003). The simultaneous presence of H pylori in nasal mucous and lacrimal secretions was 13.6% in Group II. H pylori positivity in nasal mucous and lacrimal secretions had a positive moderate correlation (r = 0.40; p = 0.0003). The present study is the first report on the presence of H pylori in lacrimal secretions through nested PCR, which suggested the presence of a number of mechanisms for H pylori transmission to lacrimal secretions.
Characterization of a secreted Chlamydia protease
Shaw, Allan C; Vandahl, Brian; Larsen, Martin Røssel
2002-01-01
Chlamydiae are obligate intracellular bacteria that are important human pathogens. The Chlamydia genomes contain orthologues to secretion apparatus proteins from other intracellular bacteria, but only a few secreted proteins have been identified. Most likely, effector proteins are secreted in ord...
Ghrelin and gastric acid secretion
Yakabi, Koji; Kawashima, Junichi; Kato, Shingo
2008-01-01
Ghrelin, a novel growth hormone-releasing peptide, was originally isolated from rat and human stomach. Ghrelin has been known to increase the secretion of growth hormone (GH), food intake, and body weight gain when administered peripherally or centrally. Ghrelin is also known to stimulate the gastric motility and the secretion of gastric acid. In the previous studies, the action of ghrelin on acid secretion was shown to be as strong as that of histamine and gastrin in in-vivo experiment. In t...
Does the Minimum Wage Cause Inefficient Rationing?
何满辉; 梁明秋
2008-01-01
By not allowing wages to dearthe labor market,the minimum wage could cause workers with low reservation wages to be rationed out while equally skilled woTkers with higher reservation wages are employed.I find that proxies for reservation wages of unskilled workers in high-impact stales did not rise relative to reservation wages in other states,suggesting that the increase in the minimum wage did not cause jobs to be allocated less efficiently.However,even if rationing is efficient,the minimum wage can still entail other efficiency costs.
[The role of economics in fair rationing].
Prenzler, A
2012-10-01
For several years academic disciplines have discussed the potential conflict between scarcity of funding and fair health care. This review article shows the necessity of involving economic scientists in this discussion as well as their contribution to rationalisation, prioritisation and rationing of health care services. Thereby, it becomes clear that rationing and justice are not a contradiction per se. The interdisciplinary discussion in Germany needs less disciplinary egotism and more willingness to seek solutions and compromises. In this context the procedures followed in other countries can serve as examples.
Medicinal cannabis: rational guidelines for dosing.
Carter, Gregory T; Weydt, Patrick; Kyashna-Tocha, Muraco; Abrams, Donald I
2004-05-01
The medicinal value of cannabis (marijuana) is well documented in the medical literature. Cannabinoids, the active ingredients in cannabis, have many distinct pharmacological properties. These include analgesic, anti-emetic, anti-oxidative, neuroprotective and anti-inflammatory activity, as well as modulation of glial cells and tumor growth regulation. Concurrent with all these advances in the understanding of the physiological and pharmacological mechanisms of cannabis, there is a strong need for developing rational guidelines for dosing. This paper will review the known chemistry and pharmacology of cannabis and, on that basis, discuss rational guidelines for dosing.
Topological Field Theory and Rational Curves
Aspinwall, Paul S; Aspinwall, Paul S.; Morrison, David R.
1993-01-01
We analyze the superstring propagating on a Calabi-Yau threefold. This theory naturally leads to the consideration of Witten's topological non-linear sigma-model and the structure of rational curves on the Calabi-Yau manifold. We study in detail the case of the world-sheet of the string being mapped to a multiple cover of an isolated rational curve and we show that a natural compactification of the moduli space of such a multiple cover leads to a formula in agreement with a conjecture by Candelas, de la Ossa, Green and Parkes.
Rationalization with ruled surfaces in architecture
Steenstrup, Kasper Hornbak
This thesis addresses the problems of rationalizing and segmenting large scale 3D models, and how to handle difficult production constraints in this area. The design choices when constructing large scale architecture are influenced by the budget. Therefore I strive to minimize the amount of time...... and material needed for production. This makes advanced free form architecture viable for low cost projects, allowing the architects to realize their designs. By pre-cutting building blocks using hot wire robots, the amount of milling necessary can be reduced drastically. I do this by rationalizing...
Rationality: A Social-Epistemology Perspective
Sylvia eWenmackers
2014-06-01
Full Text Available Both in philosophy and in psychology, human rationality has traditionally been studied from an 'individualistic' perspective. Recently, social epistemologists have drawn attention to the fact that epistemic interactions among agents also give rise to important questions concerning rationality. In previous work, we have used a formal model to assess the risk that a particular type of social-epistemic interactions lead agents with initially consistent belief states into inconsistent belief states. Here, we continue this work by investigating the dynamics to which these interactions may give rise in the population as a whole.
The Rational Hybrid Monte Carlo Algorithm
Clark, M A
2006-01-01
The past few years have seen considerable progress in algorithmic development for the generation of gauge fields including the effects of dynamical fermions. The Rational Hybrid Monte Carlo (RHMC) algorithm, where Hybrid Monte Carlo is performed using a rational approximation in place the usual inverse quark matrix kernel is one of these developments. This algorithm has been found to be extremely beneficial in many areas of lattice QCD (chiral fermions, finite temperature, Wilson fermions etc.). We review the algorithm and some of these benefits, and we compare against other recent algorithm developements. We conclude with an update of the Berlin wall plot comparing costs of all popular fermion formulations.
The Rational Hybrid Monte Carlo algorithm
Clark, Michael
2006-12-01
The past few years have seen considerable progress in algorithmic development for the generation of gauge fields including the effects of dynamical fermions. The Rational Hybrid Monte Carlo (RHMC) algorithm, where Hybrid Monte Carlo is performed using a rational approximation in place the usual inverse quark matrix kernel is one of these developments. This algorithm has been found to be extremely beneficial in many areas of lattice QCD (chiral fermions, finite temperature, Wilson fermions etc.). We review the algorithm and some of these benefits, and we compare against other recent algorithm developements. We conclude with an update of the Berlin wall plot comparing costs of all popular fermion formulations.
Rational design of protein kinase inhibitors
Yarmoluk S. M.
2013-07-01
Full Text Available Modern methodological approaches to rational design of low molecular weight compounds with specific activity in relation to predetermined biomolecular targets are considered by example of development of high effective protein kinase inhibitors. The application of new computational methods that allow to significantly improve the quality of computational experiments (in, particular, accuracy of low molecular weight compounds activity prediction without increase of computational and time costs are highlighted. The effectiveness of strategy of rational design is demonstrated by examples of several own investigations devoted to development of new inhibitors that are high effective and selective towards protein kinases CK2, FGFR1 and ASK1.
Rational homotopy theory and differential forms
Griffiths, Phillip
2013-01-01
This completely revised and corrected version of the well-known Florence notes circulated by the authors together with E. Friedlander examines basic topology, emphasizing homotopy theory. Included is a discussion of Postnikov towers and rational homotopy theory. This is then followed by an in-depth look at differential forms and de Tham's theorem on simplicial complexes. In addition, Sullivan's results on computing the rational homotopy type from forms is presented. New to the Second Edition: *Fully-revised appendices including an expanded discussion of the Hirsch lemma*Presentation of a natu
A common assembly module in injectisome and flagellar type III secretion sorting platforms.
Notti, Ryan Q; Bhattacharya, Shibani; Lilic, Mirjana; Stebbins, C Erec
2015-05-21
Translocating proteins across the double membrane of Gram-negative bacteria, type III secretion systems (T3SS) occur in two evolutionarily related forms: injectisomes, delivering virulence factors into host cells, and the flagellar system, secreting the polymeric filament used for motility. While both systems share related elements of a cytoplasmic sorting platform that facilitates the hierarchical secretion of protein substrates, its assembly and regulation remain unclear. Here we describe a module mediating the assembly of the sorting platform in both secretion systems, and elucidate the structural basis for segregation of homologous components among these divergent T3SS subtypes sharing a common cytoplasmic milieu. These results provide a foundation for the subtype-specific assembly of T3SS sorting platforms and will support further mechanistic analysis and anti-virulence drug design.
MULTI-LEVEL KEY DISTRIBUTION ALGORITHM FOR SECRET KEY RECOVERY SYSTEM
TANAPAT MAHAVEERAWAT
2015-02-01
Full Text Available Most of Multi Agent Key Recovery Systems are proposed from the assumption that Key Recovery Agents in the system have same availability of security service levelagreement and trust. Which mean, secret key will be shared to each Key Recovery Agent in equal secret’s portion. Practically, each Key Recovery Agent may have their own limitation in terms of securityservice level agreement according to economic cost, complexity and risks. This paper proposedMulti Level Key Distribution Algorithm,which the secret key can be managed into portionsharing and assignto each Key Recovery Agent (KRA according to user’s trust. Withproposed algorithm, the experimental result had shown the advantage in secret sharing size and the system had improved initssecurity from the advantage of multilevel secret key distribution capability.
Huang, Mingtao; Bai, Yunpeng; Sjostrom, Staffan L.
2015-01-01
interest in improving its protein secretion capacity. Due to the complexity of the secretory machinery in eukaryotic cells, it is difficult to apply rational engineering for construction of improved strains. Here we used high-throughput microfluidics for the screening of yeast libraries, generated by UV...... to construct efficient cell factories for protein secretion. The combined use of microfluidics screening and whole-genome sequencing to map the mutations associated with the improved phenotype can easily be adapted for other products and cell types to identify novel engineering targets, and this approach could...
Schade, D S; Eaton, R P
1977-06-01
Diabetic ketoacidosis is characterized by an excess secretion of counterregulatory hormones (glucagon, catecholamines, cortisol, and growth hormone). Experimental evidence obtained in both diabetic man and animals suggests that elevation of the plasma concentration of these hormones is necessary to initiate excess hepatic production of ketone bodies. This increase in hepatic ketogenesis in concert with inability of peripheral tissues to completely utilize ketone bodies results in clinical ketoacidosis. This hypothesis would suggest that pharmacologic control of excess counterregulatory hormone secretion would be a rational therapeutic modality to prevent diabetic ketoacidosis.
Handberg, L.; Gullström, C.; Kort, J.; Nyström, J.
2016-01-01
SharedSpaces is a WebRTC design prototype that creates a virtual media space where people can mingle and interact. Although you are in different locations, you appear side by side in front of a chosen backdrop. This interactive installation addresses spatial and social connectedness, stressing the
Blomberg, Olle
2015-01-01
undemanding for children to engage in, and therefore has the potential to play a part in fostering their understanding of other minds. Part of the functional role of shared goals is to enable agents to choose means that are appropriate to realising a goal with others rather than individually. By offering...
Hede, Børge; Elmelund Poulsen,, Johan; Christophersen, Rasmus
2014-01-01
Shared Oral Care - Forebyggelse af orale sygdomme på plejecentre Introduktion og formål: Mangelfuld mundhygiejne hos plejekrævende ældre er et alment og veldokumenteret sundhedsproblem, der kan føre til massiv udvikling af tandsygdomme, og som yderligere kan være medvirkende årsag til alvorlige...
Bødker, Keld
2006-01-01
The Danish National Board of Health has recently released a report that is intended to mark the start of a new project to establish it support for shared care in diabetes. In this paper I raise a number of concerns where lack of attention towards participation from prospective users constitute...
Graves, Bill
2011-01-01
A special breed of superintendents who have developed expertise in a particular area find ways of sharing it in other venues as outside consultants. They pull extra duty to put their special skills into practice, to give back to their communities, to stay current and grounded in the field, or to enhance their professional reputations. They teach…
Wang Ting
2010-01-01
@@ As an attitude of life The Interstoff Asia Essential Spring will be held from March 17th to 19th,2010,in Hong Kong Convention & Exhibition Centre.During this exhibition,the Interstoff Asia Directions trend committee will present its apparel fabric trend forecast for next season's wardrobes,unfolding a story of'Smart Power' of 'Sharing'.
Decreasing serial cost sharing
Hougaard, Jens Leth; Østerdal, Lars Peter Raahave
2009-01-01
The increasing serial cost sharing rule of Moulin and Shenker (Econometrica 60:1009-1037, 1992) and the decreasing serial rule of de Frutos (J Econ Theory 79:245-275, 1998) are known by their intuitive appeal and striking incentive properties. An axiomatic characterization of the increasing serial...
Promoting teachers’ knowledge sharing
Runhaar, P.R.; Sanders, K.
2016-01-01
Teachers’ professional development is nowadays seen as key in efforts to improve education. Knowledge sharing is a learning activity with which teachers not only professionalize themselves, but contribute to the professional development of their colleagues as well. This paper presents two studies,
Decreasing Serial Cost Sharing
Hougaard, Jens Leth; Østerdal, Lars Peter
The increasing serial cost sharing rule of Moulin and Shenker [Econometrica 60 (1992) 1009] and the decreasing serial rule of de Frutos [Journal of Economic Theory 79 (1998) 245] have attracted attention due to their intuitive appeal and striking incentive properties. An axiomatic characterization...
Ashbrook, Peggy
2011-01-01
There are many ways to share a collection of data and students' thinking about that data. Explaining the results of science inquiry is important--working scientists and amateurs both contribute information to the body of scientific knowledge. Students can collect data about an activity that is already happening in a classroom (e.g., the qualities…
Promoting teachers’ knowledge sharing
Runhaar, P.R.; Sanders, K.
2016-01-01
Teachers’ professional development is nowadays seen as key in efforts to improve education. Knowledge sharing is a learning activity with which teachers not only professionalize themselves, but contribute to the professional development of their colleagues as well. This paper presents two studies, a
2008-01-01
Procter & Gamble Co,extends its employee stock ownership plan to benefit its Chinese employees The Procter & Gamble Co.(P&G) launched its Chinese employee stock ownership plan(ESOP)on April 1 after five years of preparation.The plan entitles its more than 7,000 employees in China to buy P&G stocks and share its growth benefits.
Aalto, S.; Ayesta, U.; Borst, S.C.; Misra, V.; Núñez Queija, R.
2007-01-01
While the (Egalitarian) Processor-Sharing (PS) discipline offers crucial insights in the performance of fair resource allocation mechanisms, it is inherently limited in analyzing and designing differentiated scheduling algorithms such as Weighted Fair Queueing and Weighted Round-Robin. The Discrimin
Stefan Graziadei
2016-06-01
Full Text Available In this paper, I introduce a novel concept, the one of power sharing courts. Scholars of judicial politics look at the reasons behind judicial selection and the patterns of decision making within courts through the lens of ideology (left-right. However, the resulting fertile scholarly analysis has not been extended to divided societies, where the main cleavages are not partisan but ethno-national. In these societies, the liberal model of selecting judges and taking decisions within an apex court is often corrected to specifically include politically salient ascriptive cleavages (such as ethnicity/nationality/language/religion. The main thrust of my argument is that there is a model of selecting judges, taking decisions and sharing posts of influence within apex courts in divided societies that has not yet been conceptually captured: power sharing courts. In analogy to consociationalism in the political system, power sharing in the judiciary aims to solve salient inter-community conflicts by including all relevant groups in these bodies on a basis of parity or proportionality. The paper is of equal interest to scholars of constitutional courts, consociationalists, comparatists, as well as country specialists.
Hamari, Juho; Sjöklint, Mimmi; Ukkonen, Antti
2016-01-01
Information and communications technologies (ICTs) have enabled the rise of so-called “Collaborative Consumption” (CC): the peer-to-peer-based activity of obtaining, giving, or sharing the access to goods and services, coordinated through community-based online services. CC has been expected...
Promoting teachers’ knowledge sharing
Runhaar, P.R.; Sanders, K.
2016-01-01
Teachers’ professional development is nowadays seen as key in efforts to improve education. Knowledge sharing is a learning activity with which teachers not only professionalize themselves, but contribute to the professional development of their colleagues as well. This paper presents two studies, a
Planas Vilà, Mercedes
2014-01-01
The current economic situation is the reason for this conference that will be split in two main areas: first, we will focus on general concepts on rationalizing versus rationing in health care, and secondly, on rationing in the practice of clinical nutrition. According to the Spanish Royal Academy of the Language, to rationalize is to organize the production or the work in a manner such the yields are increased or the costs are reduced with the least effort. However, to ration is the action and effect of rationing or limiting the consumption of something to prevent negative consequences. In Europe, the percentage of the Gross National Product dedicated to health care progressively decreases whereas the costs of health care are ever increasing. From the economic viewpoint, this would be the main reason why the health care authorities have no other option but rationing. Until what extent the ethical principle of justice is compatible with rationing? Ethically, it seems that in order to accept rationing, not only a fair distribution of the limited resources should be achieved, but also a rational use of them. If we accept that limiting the health care allowances is necessary, we should then answer some questions: is it ethical not to limit? Who decides what is medically necessary? How is it decided? With no coherent answers to these questions it is ethically difficult to accept rationing from a healthcare viewpoint. When dealing with rationing in the practice of clinical nutrition, we should focus on how rationing impacts on hyponutrition, and more particularly on disease-related hyponutrition, since this is the focus of Clinical Nutrition. Given its importance and its implications, in several countries, including Spain, actions integrated in the European Union strategy "Together for health: a Strategic Approach for the EU 2008-2013", are being performed aimed at taking decisions for preventing and managing hyponutrition. However, restrictions persist with the
Tejeda-Dominguez, Farid; Huerta-Cantillo, Jazmin; Chavez-Dueñas, Lucia; Navarro-Garcia, Fernando
2017-03-28
The type 3 secretion system (T3SS) is essential for bacterial virulence through delivering effector proteins directly into the host cytosol. Here, we identified an alternative delivery mechanism of virulence factors mediated by the T3SS, which consists of the association of extracellularly secreted proteins from bacteria with the T3SS to gain access to the host cytosol. Both EspC, a protein secreted as an enteropathogenic Escherichia coli (EPEC) autotransporter, and YopH, a protein detected on the surface of Yersinia, require a functional T3SS for host cell internalization; here we provide biophysical and molecular evidence to support the concept of the EspC translocation mechanism, which requires (i) an interaction between EspA and an EspC middle segment, (ii) an EspC translocation motif (21 residues that are shared with the YopH translocation motif), (iii) increases in the association and dissociation rates of EspC mediated by EspA interacting with EspD, and (iv) an interaction of EspC with the EspD/EspB translocon pore. Interestingly, this novel mechanism does not exclude the injection model (i.e., EspF) operating through the T3SS conduit; therefore, T3SS can be functioning as an internal conduit or as an external railway, which can be used to reach the translocator pore, and this mechanism appears to be conserved among different T3SS-dependent pathogens.IMPORTANCE The type 3 secretion system is essential for injection of virulence factors, which are delivered directly into the cytosol of the host cells for usurping and subverting host processes. Recent studies have shown that these effectors proteins indeed travel inside an "injectisome" conduit through a single step of translocation by connecting the bacterium and host cell cytoplasms. However, all findings are not compatible with this model. For example, both YopH, a protein detected on the surface of Yersinia, and EspC, an autotransporter protein secreted by enteropathogenic E. coli, require a functional T3
Secret Key Generation From Mobility
Gungor, Onur; Koksal, C Emre
2011-01-01
We consider secret key generation from relative localization information of a pair of nodes in a mobile wireless network in the presence of a mobile eavesdropper. Our scheme consists of two phases: in the first phase, legitimate node pair exchanges beacon signals to establish localization information based on noisy observations of these beacons; in the second phase, nodes generate secret key bits via a public discussion. Our problem can be categorized under the source models of information theoretic secrecy, where the distance between the legitimate nodes acts as the observed common randomness. We characterize the achievable secret key bit rate in terms of the observation noise variance at the legitimate nodes and the eavesdropper. This work provides a framework that combines information theoretic secrecy and wireless localization, and proves that the localization information provides a significant additional resource for secret key generation in mobile wireless networks.
Policy enabled information sharing system
Jorgensen, Craig R.; Nelson, Brian D.; Ratheal, Steve W.
2014-09-02
A technique for dynamically sharing information includes executing a sharing policy indicating when to share a data object responsive to the occurrence of an event. The data object is created by formatting a data file to be shared with a receiving entity. The data object includes a file data portion and a sharing metadata portion. The data object is encrypted and then automatically transmitted to the receiving entity upon occurrence of the event. The sharing metadata portion includes metadata characterizing the data file and referenced in connection with the sharing policy to determine when to automatically transmit the data object to the receiving entity.
Rational approximations and quantum algorithms with postselection
Mahadev, U.; de Wolf, R.
2015-01-01
We study the close connection between rational functions that approximate a given Boolean function, and quantum algorithms that compute the same function using post-selection. We show that the minimal degree of the former equals (up to a factor of 2) the minimal query complexity of the latter. We gi
MINIMAL RATIONAL INTERPOLATION AND PRONYS METHOD
ANTOULAS, AC; WILLEMS, JC
1990-01-01
A new method is proposed for dealing with the rational interpolation problem. It is based on the reachability of an appropriately defined pair of matrices. This method permits a complete clarification of several issues raised, but not answered, by the so-called Prony method of fitting a linear model
Rational bargaining in games with coalitional externalities
Borm, Peter; Ju, Y.; Wettstein, D.
This paper provides a flexible strategic framework to analyze bargaining and values in environments with coalitional externalities. Within this framework we propose a new value that extends the Shapley value to partition function form games, the so-called Rational Belief Shapley (RBS) value. We
Rational Rhymes for Addressing Common Childhood Issues
Warren, Jeffrey M.
2011-01-01
Music-based interventions are valuable tools counselors can use when working with children. Specific types of music-based interventions, such as songs or rhymes, can be especially pertinent in addressing the thoughts, feelings, and behaviors of children. Rational-emotive behavior therapy (REBT) provides a therapeutic framework that encourages…
Dr. Strangelove and Irrational Collective Rationality
韩蕾
2012-01-01
Dr. Strangelove or: How I learned to Stop Worrying and Love the Bomb is a 1964 black comedy film with satire of arm races and nuclear scare by the director Stanley Kubrick. In the movie, irrational practice and ideologies manifest them⁃selves as collective rationality and result in the destruction of the earth.
Hietarinta, Jarmo; Hietarinta, Jarmo; Kajiwara, Kenji
1997-01-01
We study the rational solutions of the discrete version of Painleve's fourth equation d-PIV. The solutions are generated by applying Schlesinger transformations on the seed solutions -2z and -1/z. After studying the structure of these solutions we are able to write them in a determinantal form that includes an interesting parameter shift that vanishes in the continuous limit.
Bounded Rationality of Generalized Abstract Fuzzy Economies
Lei Wang
2014-01-01
Full Text Available By using a nonlinear scalarization technique, the bounded rationality model M for generalized abstract fuzzy economies in finite continuous spaces is established. Furthermore, by using the model M, some new theorems for structural stability and robustness to (λ,ϵ-equilibria of generalized abstract fuzzy economies are proved.
Rational Voters in a Partisanship Model
O.H. Swank (Otto)
1995-01-01
textabstractThis paper examines a voter model for the US which is interconnected with the partisan theory. In our model, voters are rational and forward-looking. They are perfectly informed about the preferences of political parties and about the state of the economy. The predictions of our voter mo
CONSTRAINED RATIONAL CUBIC SPLINE AND ITS APPLICATION
Qi Duan; Huan-ling Zhang; Xiang Lai; Nan Xie; Fu-hua (Frank) Cheng
2001-01-01
In this paper, a kind of rational cubic interpolation functionwith linear denominator is constructed. The constrained interpolation with constraint on shape of the interpolating curves and on the second-order derivative of the interpolating function is studied by using this interpolation, and as the consequent result, the convex interpolation conditions have been derived.
Robust identification for rational fractional transfer functions
王书宁
1997-01-01
An algorithm is proposed for robust identification of a rational fractional transfer function with a fixed degree under the framework of worst-case/deterministic robust identification. The convergence of the algorithm is proven. Its feasibility is shown with a numerical example.
Adaptive Rationality, Adaptive Behavior and Institutions
Volchik Vyacheslav, V.
2015-12-01
Full Text Available The economic literature focused on understanding decision-making and choice processes reveals a vast collection of approaches to human rationality. Theorists’ attention has moved from absolutely rational, utility-maximizing individuals to boundedly rational and adaptive ones. A number of economists have criticized the concepts of adaptive rationality and adaptive behavior. One of the recent trends in the economic literature is to consider humans irrational. This paper offers an approach which examines adaptive behavior in the context of existing institutions and constantly changing institutional environment. It is assumed that adaptive behavior is a process of evolutionary adjustment to fundamental uncertainty. We emphasize the importance of actors’ engagement in trial and error learning, since if they are involved in this process, they obtain experience and are able to adapt to existing and new institutions. The paper aims at identifying relevant institutions, adaptive mechanisms, informal working rules and practices that influence actors’ behavior in the field of Higher Education in Russia (Rostov Region education services market has been taken as an example. The paper emphasizes the application of qualitative interpretative methods (interviews and discourse analysis in examining actors’ behavior.
Heterogeneous Parking Market Subject to Parking Rationing
Saeed Asadi Bagloee
2015-01-01
Full Text Available Different types of drivers and parking spaces delineate a heterogeneous parking market for which the literature has yet to provide a model applicable to the real world. The main obstacle is computational complexities of considering various parking restrictions along with traffic congestion on the road network. In this study, the heterogeneity aspects are considered within a Logit parking choice model. A mathematical programming problem was introduced to explicitly consider parking capacities and parking rationing constraints. The parking rationing is defined as any arrangement to reserve parking space for some specific demand such as parking permit, private parking, VIP parking, and different parking durations. Introduction of parking rationing in the presence of other constraints is a unique factor in this study which makes the model more realistic. The algorithm was tested on a central business district case study. The results prove that the algorithm is able to converge rapidly. Among the algorithm’s output are shadow prices of the parking capacity and parking rationing constraints. The shadow prices contain important information which is key to addressing a variety of parking issues, such as the location of parking shortages, identification of fair parking charges, viability of parking permits, and the size of reserved parking.
Multiple Equilibria in Noisy Rational Expectations Economies
Palvolgyi, Domotor; Venter, Gyuri
This paper studies equilibrium uniqueness in standard noisy rational expectations economies with asymmetric or differential information a la Grossman and Stiglitz (1980) and Hellwig (1980). We show that the standard linear equilibrium of Grossman and Stiglitz (1980) is the unique equilibrium...