Maintaining regularity and generalization in data using the minimum description length principle and genetic algorithm: case of grammatical inference

In this paper, a genetic algorithm with minimum description length (GAWMDL) is proposed for grammatical inference. The primary challenge of identifying a language of infinite cardinality from a finite set of examples should know when to generalize and specialize the training data. The minimum description length principle that has been incorporated addresses this issue is discussed in this paper. Previously, the e-GRIDS learning model was proposed, which enjoyed the merits of the minimum description length principle, but it is limited to positive examples only. The proposed GAWMDL, which incorporates a traditional genetic algorithm and has a powerful global exploration capability that can exploit an optimum offspring. This is an effective approach to handle a problem which has a large search space such the grammatical inference problem. The computational capability, the genetic algorithm poses is not questionable, but it still suffers from premature convergence mainly arising due to lack of population diversity. The proposed GAWMDL incorporates a bit mask oriented data structure that performs the reproduction operations, creating the mask, then Boolean based procedure is applied to create an offspring in a generative manner. The Boolean based procedure is capable of introducing diversity into the population, hence alleviating premature convergence. The proposed GAWMDL is applied in the context free as well as regular languages of varying complexities. The computational experiments show that the GAWMDL finds an optimal or close-to-optimal grammar. Two fold performance analysis have been performed. First, the GAWMDL has been evaluated against the elite mating pool genetic algorithm which was proposed to introduce diversity and to address premature convergence. GAWMDL is also tested against the improved tabular representation algorithm. In addition, the authors evaluate the performance of the GAWMDL against a genetic algorithm not using the minimum description length principle. Statistical tests demonstrate the superiority of the proposed algorithm. Overall, the proposed GAWMDL algorithm greatly improves the performance in three main aspects: maintains regularity of the data, alleviates premature convergence and is capable in grammatical inference from both positive and negative corpora

Controlling the Ultrafast Dynamics of HD+ by the Carrier-Envelope Phases of an Ultrashort Laser Pulse: A Quasi-Classical Dynamics Study

A theoretical study on the coupled electron-nuclear dynamics of HD+ molecular ions under ultrashort, intense laser pulses is performed by employing a well-established quasi-classical model. The influence of the laser carrier-envelope phase on various channel (H + D+, D + H+, and H+ + D+) probabilities is investigated at different laser field intensities. The carrier-envelope phase is found to govern the dissociation (H + D+ and D + H+) and Coulomb explosion (H+ + D+) channel probabilities. The kinetic energy release distributions of the fragments are also found to be sensitive to the carrier-envelope phase of the laser pulse. Our results are in agreement with the previously reported quantum dynamics studies and experiments

Optical observations of the bright long duration peculiar GRB 021004 afterglow

The CCD magnitudes in Johnson $B,V$ and Cousins $R$ and $I$ photometric passbands are determined for the bright long duration GRB 021004 afterglow from 2002 October 4 to 16 starting $\sim$ 3 hours after the $\gamma-$ray burst. Light curves of the afterglow emission in $B$,$V$,$R$ and $I$ passbands are obtained by combining these measurements with other published data. The earliest optical emission appears to originate in a revese shock. Flux decay of the afterglow shows a very uncommon variation relative to other well-observed GRBs. Rapid light variations, especially during early times ($\Delta t < 2$ days) is superposed on an underlying broken power law decay typical of a jetted afterglow. The flux decay constants at early and late times derived from least square fits to the light curve are $0.99\pm0.05$ and $2.0\pm0.2$ respectively, with a jet break at around 7 day. Comparison with a standard fireball model indicates a total extinction of $E(B-V)=0.20$ mag in the direction of the burst. Our low-resolution spectra corrected for this extinction provide a spectral slope $\beta = 0.6\pm0.02$. This value and the flux decay constants agree well with the electron energy index $p\sim 2.27$ used in the model. The derived jet opening angle of about $7^{\circ}$ implies a total emitted gamma-ray energy $E_{\gamma} = 3.5\times10^{50}$ erg at a cosmological distance of about 20 Gpc. Multiwavelength observations indicate association of this GRB with a star forming region, supporting the case for collapsar origin of long duration GRBs.Comment: 19 pages, 3 figures, BASI, 31, 1

Are We Seeing Magnetic Axis Reorientation in the Crab and Vela Pulsars?

Variation in the angle $\alpha$ between a pulsar's rotational and magnetic axes would change the torque and spin-down rate. We show that sudden increases in $\alpha$, coincident with glitches, could be responsible for the persistent increases in spin-down rate that follow glitches in the Crab pulsar. Moreover, changes in $\alpha$ at a rate similar to that inferred for the Crab pulsar account naturally for the very low braking index of the Vela pulsar. If $\alpha$ increases with time, all pulsar ages obtained from the conventional braking model are underestimates. Decoupling of the neutron star liquid interior from the external torque cannot account for Vela's low braking index. Variations in the Crab's pulse profile due to changes in $\alpha$ might be measurable.Comment: 14 pages and one figure, Latex, uses aasms4.sty. Accepted to ApJ Letter

Field evaluation of Indian gooseberry (Emblica officinalis) accessions for yield, fruit quality and antioxidant potential

Ten diverse promising genotypes of Indian gooseberry (Emblica officinalis Gaertn.) along with two commercial varieties, viz, NA-6 and NA-7 were evaluated during the year 2013 and 2014 for commercial potential based on tree growth and physico-chemical characteristics. Maximum plant height was recorded in genotype CISH A-19 (7.11m) and minimum in NA-6 (4.13m). Plant spread in East-West and North-South directions varied from 3.01-5.13m and 2.91-4.89m respectively, while plant girth was recorded maximum in CISH A-19 (63.88 cm). Pulp weight varied from (22.91-33.92g), recorded highest in genotype CISH A-31 (33.92g) while lowest weight was found in CISH A-17 (22.91g). Large variations in fruit shape, viz. oval round, flattened round, round, conical, flattened oblong and flattened oval was noticed amongst the genotypes. Similarly, fruit colour at maturity among different genotypes recorded as green, light green and pinkish. Fruit weight varied from 24.37 to 35.41g among the different genotypes being highest in genotype CISH A-19 (35.41g) which is significantly higher than the standard check varieties NA-6 (28.49g) and NA-7 (30.30g). No significant difference was recorded amongst the studied material with respect to standard check for fruit length and fruit diameter. Significantly higher percentage of pulp was recorded in CISH A-31 (95.60%) compared to check NA-6 (94.77%) and NA-7 (95.01%). Stone size with respect to length ranged from 1.02-1.15cm being highest in CISH-A-15 (1.15 cm) while stone width was recorded maximum in CISH A-1 and CISH A-2 (1.06cm). Stone weight varied from 1.46-1.57g being maximum recorded in CISH A-19 (1.57g) and minimum in CISH A-17 (1.46g). Considerable variation in fruit yield (26.14 to 52.50 kg/tree) from 6 years old trees were observed. Highest fruit yield was recorded in genotype CISH A-31 (52.50 kg/tree) followed by CISH A-3 (48.11 kg/tree) which is highly significant compared to standard check NA-6 (32.90 kg/tree) and NA-7 (35.76kg/tree). The chemical parameters, viz. vitamin-C content ranged from 309.66-473.13 mg/100g, TSS (9.3-10.6 0B), acidity (1.49-2.88%), total sugar content (5.66-6.89%), polyphenol content (0.633-1.427 mg/100g) and FRAP activity (102.01-235.76 mg/100g FeSO4) among different accessions evaluated. Conclusively, based on yield, associated physico-chemical traits and antioxidant value, genotype CISH A-31 found most promising and can be recommended for future commercialization

Star formation in young star cluster NGC 1893

We present a comprehensive multi-wavelength study of the star-forming region NGC 1893 to explore the effects of massive stars on low-mass star formation. Using near-infrared colours, slitless spectroscopy and narrow-band $H\alpha$ photometry in the cluster region we have identified candidate young stellar objects (YSOs) distributed in a pattern from the cluster to one of the nearby nebulae Sim 129. The $V, (V-I)$ colour-magnitude diagram of the YSOs indicates that majority of these objects have ages between 1 to 5 Myr. The spread in the ages of the YSOs may indicate a non-coeval star formation in the cluster. The slope of the KLF for the cluster is estimated to be $0.34\pm0.07$, which agrees well with the average value ($\sim 0.4$) reported for young clusters. For the entire observed mass range $0.6 < M/M_\odot \le 17.7$ the value of the slope of the initial mass function, $`\Gamma$', comes out to be $-1.27\pm0.08$, which is in agreement with the Salpeter value of -1.35 in the solar neighborhood. However, the value of $`\Gamma$' for PMS phase stars (mass range $0.6 < M/M_\odot \le 2.0$) is found to be $-0.88\pm0.09$ which is shallower than the value ($-1.71\pm0.20$) obtained for MS stars having mass range $2.5 < M/M_\odot \le 17.7$ indicating a break in the slope of the mass function at $\sim 2 M_\odot$. Estimated $`\Gamma$' values indicate an effect of mass segregation for main-sequence stars, in the sense that massive stars are preferentially located towards the cluster center. The estimated dynamical evolution time is found to be greater than the age of the cluster, therefore the observed mass segregation in the cluster may be the imprint of the star formation process. There is evidence for triggered star formation in the region, which seems to govern initial morphology of the cluster.Comment: Accepted for the publication in MNRAS, 21 pages, 26 figures, 10 table

PENGARUH PENDAPATAN TERHADAP KONSUMSI DAGING BABI DI KECAMATAN WANEA KELURAHAN RANOTANA WERU

ABSTRACT INCOME EFFECT ON CONSUMPTION OF PORK IN WANEA DISTRCT RANOTANA WERU VILLAGE This study aims to determine the effect of family income to the consumption of pork and substitutes, in Wanea district, Ranotana Weru village. The survey method used to obtain secondary data and primary data. Samples were obtained by purposive sampling, and to get answers from the purpose of this study, the formula of multiple regression analysis is used: C = b0 + b1 x1 + b2 x2 + b3 x3, and obtained the analysis of the influence of family income on the consumption of pork in Ranotana Weru village as the following: C = 59.44 + 1.38 (x1) + 0,018 (x2) + 4.97 (x3) R2 = 0.95. From the results of the equation, the value of the intercept of 59.44 indicates that no change in the price of pork, the price of substitutes and without changes in income, then the people in Ranotana Weru village keep eating pork amounted to 59.44 grams (per person?). See the regression coefficient value of the price of pork of 1.38, meaning in any increase in the price of pork Rp 1.000, the consumption of pork decreased by 1.38 grams (per person?),  Seethe price regression coefficient value of substitutes0.018, means any increase in the price of substitutes Rp 1.000, the substitution of consumption goods rose by 0,018 grams. See the earnings darai regression coefficient 4.97, meaning any increase in revenue to Rp 1.000, the consumption of pork will rise by 4.97 grams and R2 value of 0.95 indicates that variations in rise and fall of the consumption of pork and substitutes at 95 % influenced by factors family income and sisnya 5% influenced by other factors not included in the model equations. Family income significantly affect the consumption of pork and substitutes in the village ranotana Weru. This is evidenced by the results of the t test of 0.786 is smaller than Ttabel 2,000.   Keywords: Income, consumption of pork, substitute