Low Density Lattice Codes

Low density lattice codes (LDLC) are novel lattice codes that can be decoded efficiently and approach the capacity of the additive white Gaussian noise (AWGN) channel. In LDLC a codeword x is generated directly at the n-dimensional Euclidean space as a linear transformation of a corresponding integer message vector b, i.e., x = Gb, where H, the inverse of G, is restricted to be sparse. The fact that H is sparse is utilized to develop a linear-time iterative decoding scheme which attains, as demonstrated by simulations, good error performance within ~0.5dB from capacity at block length of n = 100,000 symbols. The paper also discusses convergence results and implementation considerations.Comment: 24 pages, 4 figures. Submitted for publication in IEEE transactions on Information Theor

Bursting the selfishness bubble

Milton Friedman, probably the most influential economist of the 20th century, wrote “the social responsibility of business is to increase its profits”. I propose that striving for profit at all costs leads people, including business executives, to think in a selfishness bubble. That is, people’s interests shape the way they both perceive and choose information, informing their decisions. Thinking in a selfishness bubble is dangerous as it can lead to shortsighted decisions and poor-quality products. For example, when safety is sacrificed for profit. To burst the selfishness bubble, behavioral science and in particular, the field of behavioural ethics, should inform policy and industry leaders about the best ways to adopt a long-term perspective when designing companies and policy

Universal criteria for blind deconvolution

We present necessary and sufficient conditions for blind equalization/deconvolution (without observing the input) of an unknown, possible non-minimum phase linear time invariant system (channel). Based on that, we propose a family of optimization criteria and prove that their solution correspond to the desired response. These criteria, and the associated gradient-search algorithms, involve the computation of high order cumulants. The proposed criteria are universal in the sense that they do not impose any restrictions on the probability distrbution of the input symbols. We also address the problem of additive noise in the system and show that in several important cases, e.g. when the additive noise is Gaussian, the proposed criteria are unaffected.Funding was provided by the Office of Naval Research under Grant Number NOO014-90-J-1109

The truth comes naturally! Does it?

Does the truth come naturally? And by implication, does this mean that a lie may not come as naturally as the truth? Truth-Default Theory and the Information Manipulation Theory 2 diverge in their opinion on whether people's natural response is to lie or tell the truth. In line with Truth-Default Theory, cognitive psychology research supports the notion that the truth is the default in human communication. Information Manipulation Theory 2 holds that lying may come as naturally as, or even more naturally than, truth telling, and recent social psychology research supports this possibility. We suggest that motivation may explain the divergence between the two theories and the two lines of research. We raise the hypothesis that truth telling may be the natural response absent clear motivations to lie (hence, most human communication) and that lying may prevail as the automatic reaction when it brings about important self-profit. We hope that this hypothesis will stimulate new research that will allow for bridging the theoretical and empirical findings that seem discrepant at first and show when the truth (vs. the lie) comes naturally

Isolation and characterization of Rhizobium sp. from a collar rot tolerant groundnut (Arachis hypogaea L.) variety

Groundnut, a major pulse crop, is prone to fungal diseases especially collar rot at seed germination and early seedling stage. In the present study, symbiotic bacteria was isolated and characterised from a collar rot resistant groundnut variety, Mallika and identified as Rhizobium pongamiae following biochemical and molecular characterization (NCBI Acc. No. MK770416). The bacterial isolate on cross inoculation, may be useful in improving crop productivity and enhancing collar rot disease tolerance in susceptible crops

The collaborative roots of corruption

Cooperation is essential for completing tasks that individuals cannot accomplish alone. Whereas the benefits of cooperation are clear, little is known about its possible negative aspects. Introducing a novel sequential dyadic die-rolling paradigm, we show that collaborative settings provide fertile ground for the emergence of corruption. In the main experimental treatment the outcomes of the two players are perfectly aligned. Player A privately rolls a die, reports the result to player B, who then privately rolls and reports the result as well. Both players are paid the value of the reports if, and only if, they are identical (e.g., if both report 6, each earns €6). Because rolls are truly private, players can inflate their profit by misreporting the actual outcomes. Indeed, the proportion of reported doubles was 489 higher than the expected proportion assuming honesty, 48 higher than when individuals rolled and reported alone, and 96 higher than when lies only benefited the other player. Breaking the alignment in payoffs between player A and player B reduced the extent of brazen lying. Despite player B's central role in determining whether a double was reported, modifying the incentive structure of either player A or player B had nearly identical effects on the frequency of reported doubles. Our results highlight the role of collaboration—particularly on equal terms—in shaping corruption. These findings fit a functional perspective on morality. When facing opposing moral sentiments—to be honest vs. to join forces in collaboration—people often opt for engaging in corrupt collaboration