Syndrome source coding and its universal generalization

A method of using error-correcting codes to obtain data compression, called syndrome-source-coding, is described in which the source sequence is treated as an error pattern whose syndrome forms the compressed data. It is shown that syndrome-source-coding can achieve arbitrarily small distortion with the number of compressed digits per source digit arbitrarily close to the entropy of a binary memoryless source. A universal generalization of syndrome-source-coding is formulated which provides robustly-effective, distortionless, coding of source ensembles

Coordinated design of coding and modulation systems

The joint optimization of the coding and modulation systems employed in telemetry systems was investigated. Emphasis was placed on formulating inner and outer coding standards used by the Goddard Spaceflight Center. Convolutional codes were found that are nearly optimum for use with Viterbi decoding in the inner coding of concatenated coding systems. A convolutional code, the unit-memory code, was discovered and is ideal for inner system usage because of its byte-oriented structure. Simulations of sequential decoding on the deep-space channel were carried out to compare directly various convolutional codes that are proposed for use in deep-space systems

First positron annihilation lifetime measurement of Pu

We have made the first measurement of defects in an aged sample of {delta} phase, Ga stabilized Pu, using positron annihilation lifetime spectroscopy. This measurement validates the procedure necessary to perform measurements on this highly toxic material and obtain data representative of sample conditions. Comparison of the positron annihilation lifetime analysis of the data with calculated values suggests that He filled vacancies or vacancy clusters dominate the defect population. Such defects are the necessary precursor to void growth and swelling. The evolution of defects resulting from the radioactive decay of Pu during its life in the stockpile is one of the unknown quantities affecting our confidence in predictions of the limit on stockpile components. Radiation damage leads to changes in the size and strength of metals studied for reactor and accelerator use and similar effects may be expected in Pu. The evolution of radiation produced vacancies into larger void structures and accompanying macroscopic swelling may occur in Pu at some age. A detailed understanding of the defects in self irradiated Pu is required to predict the time scale of void swelling and related radiation effects. 1 fig

Derivation of consistent hard rock (1000<Vs<3000 m/s) GMPEs from surface and down-hole recordings: Analysis of KiK-net data

A key component in seismic hazard assessment is the estimation of ground motion for hard rock sites, either for applications to installations built on this site category, or as an input motion for site response computation. Empirical ground motion prediction equations (GMPEs) are the traditional basis for estimating ground motion while VS30 is the basis to account for site conditions. As current GMPEs are poorly constrained for VS30 larger than 1000 m/s, the presently used approach for estimating hazard on hard rock sites consists of “host-to-target” adjustment techniques based on VS30 and κ0 values. The present study investigates alternative methods on the basis of a KiK-net dataset corresponding to stiff and rocky sites with 500 < VS30 < 1350 m/s. The existence of sensor pairs (one at the surface and one in depth) and the availability of P- and S-wave velocity profiles allow deriving two “virtual” datasets associated to outcropping hard rock sites with VS in the range [1000, 3000] m/s with two independent corrections: 1/down-hole recordings modified from within motion to outcropping motion with a depth correction factor, 2/surface recordings deconvolved from their specific site response derived through 1D simulation. GMPEs with simple functional forms are then developed, including a VS30 site term. They lead to consistent and robust hard-rock motion estimates, which prove to be significantly lower than host-to-target adjustment predictions. The difference can reach a factor up to 3–4 beyond 5 Hz for very hard-rock, but decreases for decreasing frequency until vanishing below 2 Hz

The secret perks of being a middle child: A study on the relationship of birth order and proactive behavior as moderated by gender, self-esteem and sibship size

Birth order has commonly been recognized to be part of a person’s asset, primarily due to the fact that literature supports evidence of distinctive personalities present to one over the other. However, a single birth order position namely the middle-born position has been recorded to mostly take the modest quality of characteristics, hardly been regarded to obtain a competitive personality. What this study therefore intends to find out is to reveal how exactly each birth order position is differentiated based on their proactive behaviors and whether such distinction can be moderated by their self-esteem and gender. Pushing further to the potential of the study, the researchers also focused on the data of middle children, unveiling whether such behavior may actually be moderated by their sibship size. Three hundred randomly selected university students was ask to answer a pen and paper format questionnaire composed of randomly distributed items from the Scale of Proactive Behavior and the Rosenberg test of Self-esteem. Each student where asked to list down how many siblings do they have including themselves in order to verify their birth order within their sibhip. As predicted, birth order indeed has a significant relationship with proactive behavior as moderated by self-esteem. Although it was hypothesized that middle-borns have the highest level of proactive behavior, they came in second from the youngest down to the oldest with the lowest level of proactive behavior as determined by two constructs namely anticipatory and opportunity seeking behaviors. Also, although it was predicted that attaining high self-esteem would be a pre-requisite in attaining high proactive behavior, they came in second from the youngest down to the oldest with the lowest level of proactive behavior as determined by two construct namely anticipatory and opportunity seeking behaviors. Also, although it was predicted that attaining high self-esteem would be a pre-requisite in attaining high proactive behavior, the results showed that the middle-borns, the group who had the lowest self-esteem, was not the group with the lowest proactive behavior but instead, it was the firstborns who was proved to have the highest self-esteem. Furthermore, it was found that among middle-borns, sibship size has a significant relationship with proactive behavior. Middle-borns with lower sibship size can be associated with high proactive behavior than those with larger number of family members. The results showed different implications, including having high self-esteem may not exactly always be a pre-requisite of proactive behavior and the concept of human agency where the state of being a middle-born may not exactly undermine the power of an individual to be proactive

Stacking efficiency of terrestrial Plant-Microbial Fuel Cells growing

Plant-Microbial Fuel Cells (PMFCs) are an emerging type of renewable energy that generates an electric current through the consumption of rhizodeposits by exoelectrogenic bacteria that lives in the rhizosphere of the plant. Since the plant is not harmed by the energy-harvesting process, PMFC technology has the potential to simultaneously produce food (biomass) and generate electricity. As of now, power densities of PMFCs have remained low and commercialization is not yet possible. To achieve higher power densities, the stacking behaviour of PMFCs needs to be studied. In this study, several cells growing Ocimum basilicum (basil) and Origanum vulgare (oregano) were constructed and evaluated. Upon stacking, it was shown that the constructed PMFCs did indeed behave like batteries, where the voltage of cells connected in series are additive, and that the voltage of cells connected in parallel are constant. The actual values of voltage of stacked cells are similar to the expected value (α=0.05). Cumulative stacking tests revealed that there is no apparent loss in voltage upon stacking up to 9 cells growing O. basilicum. Further computation of power and power densities have proven that stacking is a viable method of amplifying electricity generation in PMFCs, as both increased with increasing number of cells connected in series