An Optimally Fair Coin Toss

We address one of the foundational problems in cryptography: the bias of coin-flipping protocols. Coin-flipping protocols allow mutually distrustful parties to generate a common unbiased random bit, guaranteeing that even if one of the parties is malicious, it cannot significantly bias the output of the honest party. A classical result by Cleve (Proceedings of the 18th annual ACM symposium on theory of computing, pp 364–369, 1986) showed that for any two-party \(r\)-round coin-flipping protocol there exists an efficient adversary that can bias the output of the honest party by \(\varOmega (1/r)\). However, the best previously known protocol only guarantees \(O(1/\sqrt{r})\) bias, and the question of whether Cleve’s bound is tight has remained open for more than 20 years. In this paper, we establish the optimal trade-off between the round complexity and the bias of two-party coin-flipping protocols. Under standard assumptions (the existence of oblivious transfer), we show that Cleve’s lower bound is tight: We construct an \(r\)-round protocol with bias \(O(1/r)\).     

Leading by example: The case of leader OCB.

The importance of leading by personal example or role modeling for effective leadership has been recognized in many leadership theories. However, leaders' ability to influence group behavior through exemplary behavior has received little attention in empirical work. This study explores leading by example through theoretical development and empirical testing of a moderated mediation model of the potential effects of leader organizational citizenship behavior (OCB). This model suggests that a leader's OCB may promote group OCB directly and indirectly by enhancing the group's belief that OCB is worthy. It also specifies the moderators of the direct and indirect effects of leader OCB on group OCB. Data from 683 members of 67 intact work groups, 67 group managers, and their supervisors support the hypothesized model. The theoretical and practical implications of these findings are discussed. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Imagined positive emotions and inhibitory control: The differentiated effect of pride versus happiness.

Inhibitory control is a cognitive mechanism that contributes to successful self-control (i.e., adherence to a long-term goal in the face of an interfering short-term goal). This research explored the effect of imagined positive emotional events on inhibition. The authors proposed that the influence of imagined emotions on inhibition depends on whether the considered emotion corresponds to the attainment of a long-term goal (i.e., pride) or a short-term goal (i.e., happiness). The authors predicted that in an antisaccade task that requires inhibition of a distractor, imagining a happiness-eliciting event is likely to harm inhibitory processes compared with imagining a pride-eliciting event, because the former but not the latter primes interfering short-term goals. The results showed that imagining a happiness-eliciting event decreased inhibition relative to imagining a pride-eliciting event. The results suggest a possible mechanism underlying the role of imagined positive emotions in pursuit of goals that require self-control. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Active learning: When is more better? The case of resident physicians’ medical errors.

An active learning climate facilitates new knowledge acquisition by encouraging employees to ask questions, seek feedback, reflect on potential results, explore, and experiment. These activities, however, also increase a learner’s chances of erring. In high-reliability organizations, any error is unacceptable and may well be life threatening. The authors use the example of resident physicians to suggest that by adjusting the conditions of priority of safety and managerial safety practices, organizations can balance these potentially conflicting activities. Participants in the study were 123 residents from 25 medical wards. Results demonstrated that the positive linear relationship between priority of safety and safety performance, demonstrated in earlier studies, existed only when the active learning climate was low. When the active learning climate was high, results demonstrated a U-shaped curvilinear relationship between priority of safety and number of errors. In addition, high managerial safety practices mitigated the number of errors as a result of the active learning climate. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Correction to: The Implications of Post-Fire Physical Features of Cylindrical 18650 Lithium-Ion Battery Cells

Fire Technology - The original publication of the article unfortunately contained a mistake in Figure 2c.     

长江重要堤防隐蔽工程建设投资对扩大内需、拉动经济的作用和影响

长江重要堤防隐蔽工程是党中央、国务院实施积极财政政策进行长江堤防建设的重要组成部分，隐蔽工程既是重要的基础设施，也是重要的环境保护工程，隐蔽工程与其他行业的关联性很强，对众多行业具有巨大的带动作用，有效地扩大了内需，拉动了经济增长。     

Measurement of the Neutron Lifetime Using a Gravitational Trap and a Low-Temperature Fomblin Coating

We present a new value for the neutron lifetime of 878.5 ± 0.7_stat. ± 0.3_syst. This result differs from the world average value by 6.5 standard deviations and by 5.6 standard deviations from the previous most precise result. However, this new value for the neutron lifetime together with a β-asymmetry in neutron decay, A₀, of −0.1189(7) is in a good agreement with the Standard Model.     

A second-order maximum principle for discrete-time bilinear control systems with applications to discrete-time linear switched systems

A powerful approach for analyzing the stability of continuous-time switched systems is based on using optimal control theory to characterize the “most unstable” switching law. This reduces the problem of determining stability under arbitrary switching to analyzing stability for the specific “most unstable” switching law. For discrete-time switched systems, the variational approach received considerably less attention. This approach is based on using a first-order necessary optimality condition in the form of a maximum principle (MP), and typically this is not enough to completely characterize the “most unstable” switching law. In this paper, we provide a simple and self-contained derivation of a second-order necessary optimality condition for discrete-time bilinear control systems. This provides new information that cannot be derived using the first-order MP. We demonstrate several applications of this second-order MP to the stability analysis of discrete-time linear switched systems.     

Environmental Policy Analysis, Peer Reviewed: Assessing the Environmental Movement's Attitudes Toward Risk Assessment

Risk Assessment.