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21.
A newly developed personality taxonomy suggests that self-esteem, locus of control, generalized self-efficacy, and neuroticism form a broad personality trait termed core self-evaluations. The authors hypothesized that this broad trait is related to motivation and performance. To test this hypothesis, 3 studies were conducted. Study 1 showed that the 4 dispositions loaded on 1 higher order factor. Study 2 demonstrated that the higher order trait was related to task motivation and performance in a laboratory setting. Study 3 showed that the core trait was related to task activity, productivity as measured by sales volume, and the rated performance of insurance agents. Results also revealed that the core self-evaluations trait was related to goal-setting behavior. In addition, when the 4 core traits were investigated as 1 nomological network, they proved to be more consistent predictors of job behaviors than when used in isolation. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
22.
CBC MAC for Real-Time Data Sources 总被引:1,自引:0,他引:1
The Cipher Block Chaining (CBC) Message Authentication Code (MAC) is an authentication method which is widely used in practice.
It is well known that the use of the CBC MAC for variable length messages is not secure, and a few rules of thumb for the
correct use of the CBC MAC are known by folklore. The first rigorous proof of the security of CBC MAC, when used on fixed
length messages, was given only recently by Bellare et al.[3]. They also suggested variants of CBC MAC that handle variable-length
messages but in these variants the length of the message has to be known in advance (i.e., before the message is processed).
We study CBC authentication of real-time applications in which the length of the message is not known until the message ends,
and furthermore, since the application is real-time, it is not possible to start processing the authentication until after
the message ends.
We first consider a variant of CBC MAC, that we call the encrypted CBC MAC (EMAC), which handles messages of variable unknown lengths. Computing EMAC on a message is virtually as simple and as efficient
as computing the standard CBC MAC on the message. We provide a rigorous proof that its security is implied by the security
of the underlying block cipher. Next, we argue that the basic CBC MAC is secure when applied to a prefix-free message space.
A message space can be made prefix-free by also authenticating the (usually hidden) last character which marks the end of
the message.
Received 16 September 1997 and revised 24 August 1999 Online publication 2 June 2000 相似文献
23.
We propose the use of generations with modern reference counting. A reference counting collector is well suited to collect the old generation, containing a large fraction of live objects that are modified infrequently. Such a collector can be combined with a tracing collector to collect the young generation, typically containing a small fraction of live objects. We have designed such a collector appropriate for running on a multiprocessor. As our building blocks, we used the sliding‐views on‐the‐fly collectors. We have implemented the new collector on the Jikes Research Java Virtual Machine (Jikes RVM) and compared it with the concurrent reference counting collector supplied with the Jikes RVM package. Our measurements demonstrate short pause times, retaining those of the original on‐the‐fly collectors and a gain in application throughput time. It turns out that a modern reference counting collector may benefit from the use of generations. Copyright © 2006 John Wiley & Sons, Ltd. 相似文献
24.
25.
Abstract We consider the tunnelling particle as a pre- and post-selected system and prove that the tunnelling time is the expectation value of the position of a ‘clock’ degree of freedom weakly coupled to it. Such a value, called a ‘weak value’, typically falls outside the eigenvalue spectrum of the operator. The appearance of unusual weak values has been associated with a unique interference structure called ‘superoscillations’ (band-limited functions which on a finite interval, approximate functions with spectra well outside their band). It is proposed that superoscillations play an important role in the interferences which give rise to superluminal effects. To demonstrate that, we consider a certain simple tunnelling barrier which allows a wave packet to travel in zero time and negligible distortion, a distance arbitrarily longer than the width of the wave packet. The peak is shown to result from a superoscillatory superposition at the tail. Similar reasoning applies to the dwell time. For this system, both the Wigner time (related to the group velocity) and a clock time correspond to superluminal velocities. 相似文献
26.
Sharly Fleischer Yuri Khodorkovsky Erez Gershnabel Yehiam Prior Ilya Sh. Averbukh 《Israel journal of chemistry》2012,52(5):414-437
Spectroscopy aims at extracting information about matter through its interaction with light. However, when performed on gas and liquid phases as well as solid phases lacking long-range order, the extracted spectroscopic features are in fact averaged over the molecular isotropic angular distributions. The reason is that light–matter processes depend on the angle between the transitional molecular dipole and the polarization of the light interacting with it. This understanding gave birth to the constantly expanding field of “laser-induced molecular alignment”. In this paper, we attempt to guide the readers through our involvement (both experimental and theoretical) in this field in the last few years. We start with the basic phenomenon of molecular alignment induced by a single pulse, continue with selective alignment of close molecular species and unidirectional molecular rotation induced by two time-delayed pulses, and lead up to novel schemes for manipulating the spatial distributions of molecular samples through rotationally controlled scattering off inhomogeneous fields and surfaces. 相似文献
27.
An automated negotiator is an intelligent agent whose task is to reach the best possible agreement. We explore a novel approach to developing a negotiation strategy, a ‘domain-based approach’. Specifically, we use two domain parameters, reservation value and discount factor, to cluster the domain into different regions, in each of which we employ a heuristic strategy based on the notions of temporal flexibility and bargaining strength. Following the presentation of our cognitive and formal models, we show in an extensive experimental study that an agent based on that approach wins against the top agents of the automated negotiation competition of 2012 and 2013, and attained the second place in 2014. 相似文献
28.
Only a few studies that have examined the effects of participation on an individual's goal acceptance and performance have been conducted within a cross-cultural context. In the present study, we tested for the contingency between the effectiveness of goal-setting strategies and cultural values. We examined three goal-setting strategies within three different cultural groups—assigned goals, goals participatively set by a group representative and the experimenter, and goals participatively set by a group. The three cultural groups studied were U.S. students (n?=?60), individualistic and having a high power distance; Israeli students from urban areas (n?=?60), collectivistic and having a low power distance; and Israeli students from kibbutzim (n?=?60), highly collectivistic and having a low power distance. Results indicated that participative strategies led to higher levels of goal acceptance and performance than the assigned strategy. Culture did not moderate the effect of goal-setting strategies on goal acceptance, but it appeared to moderate the strategy on performance for extremely difficult goals. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
29.
The paper studies broadcasting in radio networks whose stations are represented by points in the Euclidean plane (each station knows its own coordinates). In any given time step, a station can either receive or transmit. A message transmitted from station v is delivered to every station u at distance at most 1 from v, but u successfully hears the message if and only if v is the only station at distance at most 1 from u that transmitted in this time step. A designated source station has a message that should be disseminated throughout the network. All stations other than the source are initially idle and wake up upon the first time they hear the source message. It is shown in [17] that the time complexity of deterministic broadcasting algorithms depends on two parameters of the network, namely, its diameter (in hops) D and a lower bound d on the Euclidean distance between any two stations. The inverse of d is called the granularity of the network, denoted by g. Specifically, the authors of [17] present a deterministic broadcasting algorithm that works in time O (Dg) and prove that every broadcasting algorithm requires \(\varOmega \left( D \sqrt{g} \right) \) time. In this paper, we distinguish between the arbitrary deployment setting, originally studied in [17], in which stations can be placed everywhere in the plane, and the new grid deployment setting, in which stations are only allowed to be placed on a d-spaced grid. Does the latter (more restricted) setting provide any speedup in broadcasting time complexity? Although the O (Dg) broadcasting algorithm of [17] works under the (original) arbitrary deployment setting, it turns out that the \(\varOmega \left( D \sqrt{g} \right) \) lower bound remains valid under the grid deployment setting. Still, the above question is left unanswered. The current paper answers this question affirmatively by presenting a provable separation between the two deployment settings. We establish a tight lower bound on the time complexity of deterministic broadcasting algorithms under the arbitrary deployment setting proving that broadcasting cannot be completed in less than \(\varOmega (D g)\) time. For the grid deployment setting, we develop a deterministic broadcasting algorithm that runs in time \(O \left( D g^{5 / 6} \log g \right) \), thus breaking the linear dependency on g. 相似文献
30.
Michael E. Baumert Erez N. Allouche Ian D. Moore 《Canadian Metallurgical Quarterly》2005,5(4):339-349
A literature review is presented that identifies a number of areas where procedures for the engineering design of bored installations in soil using horizontal directional drilling (HDD) can be improved through a more realistic consideration of drilling fluid drag effects and skin friction coefficients. The current HDD practice of calculating annular frictional pressure loss caused by drilling fluid drag based on the assumption of concentric annular flow of a Bingham plastic fluid is demonstrated to be overly conservative. Consequently, critical design parameters, such as depth of cover, which affects crossing length, and drilling equipment size, which is selected based on anticipated pulling load, cannot be optimized. This can result in overly conservative design and unnecessary construction costs. Parameter values currently employed in HDD pulling load prediction are challenged suggesting that the viscous shear of drilling fluid is significantly less than typically quoted and that the friction coefficients often employed are not representative of all skin friction effects in HDD. A new real-time monitoring cell for large-scale HDD is described that can be used to optimize installations and to assess and update current prediction models. 相似文献