A New Goodness-of-Fit Test for the Two-Parameter Gamma Distribution

This paper proposes a new goodness-of-fit for the two-parameter distribution. It is based on a function of squared distances between empirical and theoretical quantiles of a set of observations being hypothesized to have come from the gamma distribution. The critical values of the proposed statistic are evaluated through extensive simulations of the unit-scaled gamma distributions and computations. The empirical powers of the statistic are obtained and compared with some well-known tests for the gamma distribution, and the results show that the proposed statistic can be recommended as a test for the gamma distribution.

Modeling of short duration extreme rainfall events over Lower Yamuna Catchment

Short duration rainfall estimates and their intensities for different return periods are required for many purposes such as for designing flood for hydraulic structures, urban flooding etc. An attempt has been made in this paper to Model extreme rainfall events of Short Duration over Lower Yamuna Catchment. Annual extreme rainfall series and their intensities were analysed using EVI distribution for rainstorms of short duration of 5, 10, 15, 30, 45 & 60 minutes and various return periods have been computed. The Self recording rainguage (SRRGs) data for the period 1988-2009 over the Lower Yamuna Catchment (LYC) have been used in this study. It has been found that EVI distribution fits well, tested by Kolmogorov-Smirnov goodness of fit test at 5 % level of significance for each of the station.

Genetic control of juvenile resistance to powdery mildew in spring bread wheat cultivars from the VIR collection

Background. Bread wheat (Triticum aestivum L.) is one of the major food crops of humankind. Powdery mildew, caused by Blumeria graminis f. sp. tritici, is the most destructive foliar disease capable of causing great yield losses in epidemic years. Breeding for resistance to powdery mildew is the most economical and effective way to control this disease. By now, 68 loci were identified to contain more than 90 alleles of resistance to powdery mildew in wheat. However, there is a permanent necessity in finding new sources of resistance.The objective of the present study was to characterize the seedling powdery mildew resistance in some spring bread wheat varieties from the VIR collection and determine the inheritance of powdery mildew resistance in these accessions.Materials and methods. The powdery mildew resistant varieties ‘SW Kungsjet’ (k-66036), ‘SW Kronjet’ (k-66097), ‘Boett’ (k-66353), ‘Batalj’ (k-67116), ‘Stilett’ (k-67119) ‘Pasteur’ (k-66093) were crossed with a resistant line ‘Wembley 14.31’ (k-62557) containing the Pm12 gene, and with ‘SW Milljet’ (k-64434); the variety ‘Sibirka Yartsevskaya’ (k-38587) was used as a susceptible parent and control. The hybrid populations F2 were inoculated with the fungus population from local field and evaluated. The powdery mildew population manifested virulence to Pm1a, Pm2, Pm3a-f, Pm4a-b, Pm5a, Pm6, Pm7, Pm8, Pm9, Pm10, Pm11, Pm16, Pm19, Pm28, and avirulence to Pm12. The degree of resistance was assessed on days 8 and 10 after the inoculation using the Mains and Dietz scale (Mains, Dietz, 1930). The castrated flowers in the spikes were pollinated using the twell-method (Merezhko et al., 1973). Chi-squared for goodness of fit test was used to determine deviation of the observed data from the theoretically expected segregation.Results. According phytopathological and genetic tests, juvenile resistance in the varieties ‘SW Kungsjet’, ‘SW Kronjet’, ‘Boett’, ‘Batalj’, ‘Stilett’ and ‘Pasteur’ is controlled by dominant genes, which differ from Pm1a, Pm2, Pm3a-f, Pm4a-b, Pm5a, Pm6, Pm7, Pm8, Pm9, Pm10, Pm11, Pm12, Pm16, Pm19, and Pm28. The varieties ‘SW Milljet’, ‘SW Kronjet’ and ‘Pasteur’ had identical resistance genes. Genetic control of juvenile resistance to powdery mildew in ‘Batalj’, ‘Boett’, ‘Stilett’, ‘SW Milljet’, ‘SW Kungsjet’, ‘Pasteur’ was governed by different genes.Conclusions. The varieties ‘SW Kungsjet’, ‘SW Kronjet’, ‘Boett’ have been maintaining adult and seedling resistance since 2005, and ‘Batalj’, ‘Stilett’ and ‘Pasteur’ since 2017. Seedling resistance of these varieties to local powdery mildew population is controlled by dominant genes. A high degree of resistance was displayed by ‘SW Kungsjet’ and ‘SW Kronjet’ in the Novosibirsk Province, while ‘SW Kungsjet’ was resistant to mildew populations of Tatarstan. The variety ‘Pasteur’ manifested seedling resistance to leaf rust, and ‘SW Kungsjet’ was resistant to loose smut. By summing all the results, it may be suggested that the varieties ‘SW Kungsjet’, ‘SW Kronjet’, ‘Boett’, ‘Batalj’, ‘Stilett’ and ‘Pasteur can serve as good donors of powdery mildew resistance in wheat breeding.

CORRELATION-SPECTRAL ANALYSIS OF THE TOPOGRAPHY OF ENGINEERING SURFACES AT THE NANOSCALE LEVEL

Исследована нанотопография некоторых типичных технических поверхностей и экспериментально определены характеристики профиля наношероховатости как случайного процесса - автокорреляционная функция и спектральная плотность. Показано, что для исследованных поверхностей их профилограммы могут рассматриваться как реализации случайного стационарного нормального эргодического процесса. Проведена визуальная проверка нормальности процесса сравнением экспериментальных значений ординат профиля с теоретическими значениями, подчиняющимися нормальному распределению, а также сравнением полигона частот с теоретической функцией плотности вероятности нормального распределения. Количественное подтверждение нормальности процесса выполнено с применением критерия согласия Колмогорова. Показано, что на уровне значимости p = 0,05 гипотеза о нормальности случайного процесса (профиля наношероховатости поверхности) не противоречит экспериментальным результатам. Определены интервалы корреляции рассмотренных процессов. Вид автокорреляционных функций и величины интервалов корреляции говорят о случайном характере профиля поверхности: на интервале, равном одному - двум средним значениям шага неровностей профиля его ординаты становятся практически некоррелированными. Графики спектральных плотностей свидетельствуют о том, что профиль поверхности можно рассматривать как широкополосный случайный шум с преобладанием низкочастотных составляющих. The nanotopography of some typical technical surfaces is investigated and the characteristics of the nanoroughness profile as a random process are experimentally determined - the autocorrelation function and spectral density. It is shown that for the investigated surfaces, their profilograms can be considered as realizations of a random stationary normal ergodic process. A visual check of the process normality was carried out by comparing the experimental values of the profile ordinates with theoretical values obeying the normal distribution, as well as by comparing the frequency polygon with the theoretical probability density function of the normal distribution. Quantitative confirmation of the process normality was carried out using the Kolmogorov goodness-of-fit test. It is shown that at the significance level p = 0,05, the hypothesis about the normality of a random process (surface nanoroughness profile) does not contradict the experimental results. The correlation intervals of the considered processes are determined. The form of the autocorrelation functions and the values of the correlation intervals indicate the random nature of the surface profile: in the interval equal to one or two average values of the step of the irregularities of the profile, its ordinates become practically uncorrelated. Spectral density plots indicate that the surface profile can be considered as a wide-band random noise with a predominance of low-frequency components.

Statistical Distribution of Lassa Fever in Edo State, Nigeria

Lassa fever is a severe viral infection caused by the Lassa virus and spread by contact with excretions or secretions of infected rats gaining access to food and water inside human houses and other human activity areas. Sierra Leone, the Republic of Guinea, Nigeria, and Liberia are among the nations where it is endemic with a high number of deaths recorded yearly due to Lassa fever. In Nigeria, one of the states with the highest incidence is Edo. In order to reduce and predict the spread of Lassa fever in Edo state, the trend of the disease needs to be understood. Knowledge of the statistical distribution of a disease is one of the best ways to understand the trend of the disease. Currently, existing research on the statistical distribution of Lassa fever is very rare. The present work is an attempt to initiate research on the statistical distribution of Lassa fever with data obtained on weekly cases of Lassa Fever in Edo State, Nigeria. Based on the Kolmogorov Smirnoff and Anderson Darling’s goodness of fit test for fitting distribution, the Geometric distribution outfitted the weekly confirmed incidences of Lassa fever in Edo State, Nigeria when compared with the Discrete Uniform and Poisson distributions. The study further revealed that on the average, two Lassa fever cases is recorded per week in Edo State within the study period. This number of cases per week is on the high side and should be immediately looked into.

A Modified Chi-square Type Test for Distributional Validity with Applications to Right Censored Reliability and Medical Data

In this paper, a modified Chi-square goodness-of-fit test called the modified Bagdonavičius-Nikulin goodness-of-fit test statistic is investigated and the applied for distributional validation under the right censored case. The new modified goodness-of-fit test is presented and applied for the right censored data sets. The algorithm of the censored Barzilai-Borwein is employed via a comprehensive simulation study for assessing validity of the new test. The modified Bagdonavičius-Nikulin test is applied to four real and right censored data sets. A new distribution is compared with many other competitive distributions under the new modified Bagdonavičius-Nikulin goodness-of-fit test statistic.

A test for fuzzy exponentiality based on Kullback-Leibler information

The exponential distribution has been widely used in engineering, social and biological sciences. In this paper, we propose a new goodness-of-fit test for fuzzy exponentiality using α-pessimistic value. The test statistics is established based on Kullback-Leibler information. By using Monte Carlo method, we obtain the empirical critical points of the test statistic at four different significant levels. To evaluate the performance of the proposed test, we compare it with four commonly used tests through some simulations. Experimental studies show that the proposed test has higher power than other tests in most cases. In particular, for the uniform and linear failure rate alternatives, our method has the best performance. A real data example is investigated to show the application of our test.

The performance of COVID-19 Surveillance System as timely containment strategy in Western Oromia, Ethiopia

Background COVID-19 has been swiftly spreading throughout the world ever since it emerged in Wuhan, China, in late December 2019. Case detection and contact identification remain the key surveillance objectives for effective containment of the pandemic. This study was aimed at assessing performance of surveillance in early containment of COVID 19 in Western Oromia, Ethiopia. Methods A cross-sectional study was conducted from August 1 to September 30, 2020, in the 7 kebeles of Nekemte and 2 kebeles of Shambu Town. Residents who lived there for at least the past six months were considered eligible for this study. Data were collected from community and health system at different levels using semi structured questionnaire and checklist, respectively. Participants’ health facility usage (dependent variable) and perceived risk, awareness, Socioeconomic Status, and practices (independent variable) were assessed. Bivariable analysis was computed to test the presence of an association between dependent and independent variables. Independent predictors were identified on multivariable logistic regression using a p-value of (<0.05) significance level. We have checked the model goodness of fit test by Hosmer-lemeshow test. Results One hundred seventy-nine (41%) of the participants believe that they have a high risk of contracting COVID-19 and 127 (29%) of them reported they have been visited by health extension worker. One hundred ninety-seven (45.2%) reported that they were not using health facilities for routine services during this pandemic. Except one hospital, all health facilities (92%) were using updated case definition. Three (33%) of the assessed health posts didn’t have community volunteers. On multivariable logistic regression analysis, the source of income AOR=0.30, 95% CI (0.11, 0.86), perceived level of risk AOR=3.42, 95% CI (2.04, 5.7) and not visited by health extension workers AOR=0.46, 95% CI (0.29, 0.74) were found to be independent predictors of not using health facilities during this pandemic. Conclusion Event based surveillance, both at community and health facility level, was not performing optimally in identifying potential suspects. Therefore, for effective early containment of epidemic, it is critical to strengthen event based surveillance and make use of surveillance data for tailored intervention in settings where mass testing is not feasible.

Habitat use and diet of the bear cuscus Ailurops ursinus (Temminck, 1824) in various forest ecosystem types in South Sulawesi

The population of the bear cuscus Ailurops ursinus (Temminck, 1824), an arboreal marsupial endemic to Sulawesi, Indonesia, and its satellite islands, is declining rapidly due to poaching and habitat loss, even in protected areas. However, despite concerns over its persistence, little is actually known of this secretive species. This research investigated the characteristics of the selected habitats and diet of the bear cuscus in four ecosystem types (lowland non-dipterocarp forest, lowland limestone forest, lowland monsoon deciduous forest, lowland monsoon evergreen forest). Habitat use data were collected through direct encounters and indirect observations (tracks, signs, secondary information), and analyzed using a chi-square goodness-of-fit test. Habitat characteristics and diet availability were determined using vegetation analysis. Diet data were obtained using direct observations, feed remains, and interviews. The lowland non-dipterocarp forest ecosystem was used significantly more by bear cuscus populations. Its habitats across the four ecosystem types had similar environmental conditions. Fifty-five plant species, eaten mostly as young leaves and leaf buds, encompassed the bear cuscus’ diet, with the Moraceae family being the most representative. Considering the ubiquity of Moraceae in the bear cuscus’ habitat, these results highlight the impact unchecked deforestation will continue to have on lowland Indonesia and its endemic species.