The z-test and t-test have been applied for testing the hypothesis that the population mean is equal to the specified mean value. In this paper, we will introduce the modification of the z-test and ...t-test using the double sampling scheme. We will present the operational process to implement the proposed tests. The power of the proposed test will be calculated for normal distribution, the Weibull distribution, Chi-square distribution, t-distribution and Cauchy distribution for various sample sizes. The application of the proposed tests is given using the speed of earth data. From the comparisons, it is found that the proposed test provides a higher power of the test for all distributions than the existing z-test.
Forty-six early maturing single-cross hybrids developed from twenty-eight early maturing inbred lines along with national checks (Vivek QPM 9 and Vivek Maize Hybrid 43) were evaluated over three ...locations to identify the heterotic superiority of the new cross-combinations over the best check. Correlation studies were conducted to understand the shift in relationship between different agro-climatic zones. Nine single cross hybrids were found superior to the best check at all the locations. Even though more number of hybrids (60.4 per cent) was numerically superior to the best check over the locations of zone-1, only 13 hybrids exhibited more than 10 percent superiority in zone-1. Significant negative correlation was observed for grain yield with shelling percentage (–0.306*) and days to anthesis (–0.303*) and significant positive correlation was noticed with plant height (0.350*) in zone-1. Grain yield was significantly and positive correlated with shelling percentage (0.552**) in zone-2. A significant shift in correlation values was observed for grain yield with shelling percentage, plant and ear height, ratio of ear and plant height, anthesis-silking interval and grain filling period from zone-1 to zone-2. The correlation coefficients between characters which do not shift in their association over locations/zones are more reliable for breeding single cross hybrid adaptable to diverse climatic conditions. On the other hand, significant deviation in correlation coefficient may statistically determine the appropriateness of a location to an agro-climatic zone.
Combining information from different studies is an important and useful practice in bioinformatics, including genome-wide association study, rare variant data analysis and other set-based analyses. ...Many statistical methods have been proposed to combine p-values from independent studies. However, it is known that there is no uniformly most powerful test under all conditions; therefore, finding a powerful test in specific situation is important and desirable.
In this paper, we propose a new statistical approach to combining p-values based on gamma distribution, which uses the inverse of the p-value as the shape parameter in the gamma distribution.
Simulation study and real data application demonstrate that the proposed method has good performance under some situations.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
In snow-covered mountainous terrains, topography-induced different illumination conditions would cause varying influence on the snow characteristics in the sunlit and shadowed sites owing to albedo ...variation. Since the thermal bands suffer less by the shadows as compared to the optical bands, it is imperative to investigate the effect of shadow on the optical and thermal snow indices. The investigation comprises determination of (a) difference of means between the sunlit snow cover and snow cover under shadow for thermal snow indices, optical snow cover indices and optical snow cover characteristic indices and (b) correlation coefficient of the thermal snow indices with the respective optical snow cover indices and optical snow cover characteristic indices. The study was conducted in the test sites of the Chenab basin, western Himalayas using the Landsat-8 Operational Land Imager and Thermal Infrared Sensor data.
The mean values of different snow indices exhibit significant difference between the sunlit and shadow test sites with Z-values ranging between 68.92 and 1220.39 (p<0.0001). Shadow significantly increases correlation of the thermal snow indices with the optical snow cover indices with r≥0.81, while r-values lie below 0.29 in the sunlit test site (Student's t-test, p<0.0001). On the other hand, thermal snow indices exhibit low correlation with both optical snow cover characteristic indices in either site; however, shadow induces negative correlation between them (r=−0.37 to −0.62, p<0.0001). The results ascertain the varying influence of shadow on the optical and thermal snow indices and their interrelationship, which could be significantly helpful for accurate radiative transfer modelling of snow in the light of the seasonal variation in the earth-sun geometry.
•Effect of shadow vs. sunlit on the thermal and optical snow indices was determined.•Shadow drastically reduces the thermal and optical snow indices values.•Shadow enhances correlation of thermal snow indices with optical snow indices.•Shadow inversely correlates thermal snow indices and snow cover characteristic indices.
Photorefractive keratectomy (PRK) remains a viable, safe, and efficacious option for patients wishing to correct refractive errors. One of its most significant drawbacks is pain. While post-operative ...pain has been well studied with different management options, intra-operative pain has been less well defined. The purpose of this study was to characterize intra-operative pain during PRK in regard to eye operated on, gender, excimer platform used, surgeon, and age.
A total of 134 patients (264 eyes) were prospectively randomized to undergo bilateral PRK of either the right eye first or the left eye first followed immediately by the fellow eye. In the immediate post-operative period they were surveyed using an 11-point Numeric Rating Scale regarding intra-operative pain or discomfort experienced in each eye. Resultant pain scores were then analyzed via two sample z-test and analysis of variance (ANOVA) to characterize pain overall as well as comparing first versus second eye operated on, right versus left eye, male versus female, excimer platform used, inter-surgeon variability, and age.
Of 264 eyes surveyed the mean pain experienced on a 0-10 pain scale was 1.13 (minimal discomfort). There was no statistically significant difference in pain or discomfort when comparing first versus second eye operated on, right versus left eye, male versus female, excimer platform used, operating surgeon, or age.
Intra-operative pain or discomfort experienced by patients is minimal. The absence of statistically significant differences in pain scores studied implies that standard of care procedures achieve adequate analgesia in PRK.
Hidden Markov models (HMMs) are used to analyze real-world problems. We consider an approach that constructs minimum entropy HMMs directly from a sequence of observations. If an insufficient amount ...of observation data is used to generate the HMM, the model will not represent the underlying process. Current methods assume that observations completely represent the underlying process. It is often the case that the training data size is not large enough to adequately capture all statistical dependencies in the system. It is, therefore, important to know the statistical significance level for that the constructed model representing the underlying process, not only the training set. In this paper, we present a method to determine if the observation data and constructed model fully express the underlying process with a given level of statistical significance. We use the statistics of the process to calculate an upper bound on the number of samples required to guarantee that the model has a given level significance. We provide theoretical and experimental results that confirm the utility of this approach. The experiment is conducted on a real private Tor network.
Banana belonging to the family Musaceae is the fourth most important staple food crop after rice, wheat, and maize. Genomic composition and genetic variation among 25 Musaceae genotypes, collected ...from different regions of Manipur, were evaluated using PCR–RFLP and RAPD and ISSR markers. Restriction-site variations in the internal transcribed spacers (ITS) of the nuclear ribosomal RNA genes were used to distinguish the genotypes and their genomic constitutions. PCR amplification using specific primers produced a 700-bp fragment in all the genotypes studied. This fragment that is equivalent in size to the ITS of most plants was digested with
Rsa
I, revealing 530-bp fragment that is unique to ‘A’ genome and 350 bp and 180-bp fragments that were unique to ‘B’ genome alone, and thus, the genotypes were differentiated as constituting of either the A or B genome alone or having both the A and B genomic compositions. In the wild and semi-wild genotypes, unique restriction fragments were observed. Genetic variations among the genotypes were determined using 15 RAPD and 15 ISSR markers. The respective percentage of polymorphisms for RAPD and ISSR markers was 99.79% and 99.70%. Similarity coefficients in RAPD analysis ranged from 0.14 to 0.95 and in ISSR analysis from 0.30 to 0.96. The polymorphism information content (PIC) scores for RAPD markers ranged from 0.20 to 0.29 and that of ISSR markers was 0.25 to 0.36. The Mantel Z-test between the two Jaccard’s similarity matrices gave
r
≥ 0.93, indicating a very good fit correlation between RAPD- and ISSR-based similarities. The RAPD and ISSR analyses could identify distinctive cultivars and wild species that remained conspicuously distinct in both marker systems.
We consider testing inference in inflated beta regressions subject to model misspecification. In particular, quasi-z tests based on sandwich covariance matrix estimators are described and their ...finite sample behavior is investigated via Monte Carlo simulations. The numerical evidence shows that quasi-z testing inference can be considerably more accurate than inference made through the usual z tests, especially when there is model misspecification. Interval estimation is also considered. We also present an empirical application that uses real (not simulated) data.
Gas turbines are commonly used in distributed power generation. Because of high speed nature, they require good maintenance for increased reliability and availability. Remaining useful life ...prediction is therefore an essential part of condition‐based maintenance to better foresee future state hence guaranteeing design efficiency, reduced maintenance cost, and improved safety. Gas turbines also contain a lot of sensors data that need to be processed for better prediction. In this paper, a probabilistic approach called particle filter is used for prediction. The proposed approach is tested using Turbofan degradation data provided by NASA as a benchmark problem. Meanwhile, through time the gas turbines experiences a change from normal state to degraded state attributed to aging, corrosion and erosion etc. Hence, in the context of abundant data, it is helpful to know the transition between states. For the same reason, the present paper suggests a statistical approach called Z‐test. The test results show that the proposed technique provides score and MAPE values of 559.9 and 21.6 respectively, comparable to past reported performance.
PDF
