Bayesian estimation using Lindley’s approximation of Inverted Kumaraswamy distribution based on lower record values

In this paper, we have considered estimation of unknown parameters based on lower record values for Inverted Kumaraswamy distribution. Maximum likelihood and approximate Bayes estimators based on lower record values for unknown parameters of this distribution are obtained. Lindley’s approximation (L-approximation) is used to obtain approximate Bayes estimators under DeGroot loss function based on lower record values. A Simulation study and a real data analysis are presented to illustrate the results.Publisher's Versio

Group-galaxy correlations in redshift space as a probe of the growth of structure

We investigate the use of the cross-correlation between galaxies and galaxy groups to measure redshift-space distortions (RSD) and thus probe the growth rate of cosmological structure. This is compared to the classical approach based on using galaxy auto-correlation. We make use of realistic simulated galaxy catalogues that have been constructed by populating simulated dark matter haloes with galaxies through halo occupation prescriptions. We adapt the classical RSD dispersion model to the case of the group-galaxy cross-correlation function and estimate the RSD parameter $\beta$ by fitting both the full anisotropic correlation function $\xi(r_p,\pi)$ and its multipole moments. In addition, we define a modified version of the latter statistics by truncating the multipole moments to exclude strongly non-linear distortions at small transverse scales. We fit these three observable quantities in our set of simulated galaxy catalogues and estimate statistical and systematic errors on $\beta$ for the case of galaxy-galaxy, group-group, and group-galaxy correlation functions. When ignoring off-diagonal elements of the covariance matrix in the fitting, the truncated multipole moments of the group-galaxy cross-correlation function provide the most accurate estimate, with systematic errors below 3% when fitting transverse scales larger than $10Mpc/h$. Including the full data covariance enlarges statistical errors but keep unchanged the level of systematic error. Although statistical errors are generally larger for groups, the use of group-galaxy cross-correlation can potentially allow the reduction of systematics while using simple linear or dispersion models.Comment: 18 pages, 16 figure

Hvem styrer Sørlandet? : «Er det en sammenheng mellom styreleders profil, og måten det arbeides på i styret deres?»

Masteroppgave økonomi og administrasjon - Universitetet i Agder 2016Målet med denne studien er å kartlegge styreledere og styrearbeidet i små og mellomstore bedrifter på Sørlandet. Videre ønsker jeg å finne ut om det er en sammenheng mellom styrelederes «profil» og måten det arbeides på i styret. Formålet er å få en innsikt i hvordan styrearbeidet gjøres på Sørlandet, og kunne legge frem informasjon som kan bidra til å forbedre og profesjonalisere styrearbeidet. Oppgavens empiriske grunnlag er basert på 84 spørreundersøkelser besvart av styreledere i små og mellomstore bedrifter på Sørlandet. Jeg har utformet fire kategorier for å finne ut hvordan det arbeides på i styret. Basert på datainnsamlingen har jeg utført t-tester og multiple regresjonsanalyser for å besvare forskningsspørsmålet mitt. Studien avdekker, blant annet, at det er en skjev kjønnsfordeling blant styreledere. Mine funn tyder på at det er signifikante forskjeller med mannlige og kvinnelig styreledere. Selv om styreinstruks ikke er lovpålagt i de selskapene jeg undersøker, finner jeg i testene at styreinstruks bidrar positivt til styrearbeidet. Styreledere i små og mellomstore bedrifter blir ofte rekruttert gjennom personlige nettverk. I denne oppgaven legges det frem hvordan og hvorfor dette er en negativ rekrutteringsmetode. Rekruttering av styreledere på bakgrunn av personlige nettverk bidrar ofte til at den beste kandidaten aldri blir vurdert. Videre undersøkes variabler som alder, utdanning og antall timer brukt på oppgaver som styreledere. Med hensyn til mitt forskningsspørsmål kan jeg konkludere med at mine data tyder på at det er forskjell på styrelederes bakgrunn og kompetanse, og at dette påvirker måten det arbeides på i styret

Improving fast generation of halo catalogs with higher-order Lagrangian perturbation theory

We present the latest version of Pinocchio, a code that generates catalogues of DM haloes in an approximate but fast way with respect to an N-body simulation. This code version extends the computation of particle and halo displacements up to 3rd-order Lagrangian Perturbation Theory (LPT), in contrast with previous versions that used Zeldovich approximation (ZA). We run Pinocchio on the same initial configuration of a reference N-body simulation, so that the comparison extends to the object-by-object level. We consider haloes at redshifts 0 and 1, using different LPT orders either for halo construction - where displacements are needed to decide particle accretion onto a halo or halo merging - or to compute halo final positions. We compare the clustering properties of Pinocchio haloes with those from the simulation by computing the power spectrum and 2-point correlation function (2PCF) in real and redshift space (monopole and quadrupole), the bispectrum and the phase difference of halo distributions. We find that 2LPT and 3LPT give noticeable improvement. 3LPT provides the best agreement with N-body when it is used to displace haloes, while 2LPT gives better results for constructing haloes. At the highest orders, linear bias is typically recovered at a few per cent level. In Fourier space and using 3LPT for halo displacements, the halo power spectrum is recovered to within 10 per cent up to $k_{max}\sim0.5\ h/$Mpc. The results presented in this paper have interesting implications for the generation of large ensemble of mock surveys aimed at accurately compute covariance matrices for clustering statistics.Comment: 20 pages, 20 figures, submitted to MNRA

Peranan pengetahuan keselamatan sebagai mediator dalam hubungan amalan pengurusan keselamatan dengan gelagat keselamatan dalam kalangan pekerja perkhidmatan sokongan hospital Kangar semasa krisis pandemik covid-19

Safety management practices, safety knowledge and safety performance are among the important roles in developing a safe work culture in the workplace. This study aims to test the relationship between safety management practices, safety knowledge and safety performance. This quantitative study involved a total of 190 respondents where questionnaires were distributed to employees of the hospital support services company (HSS) at Kangar Hospital. Statistical package for social science (SPSS) version 25 was used to analyze the data of this study. Descriptive analysis shows that the level of security management practices practiced by HSS is at a moderate level while the level of safety performance and safety knowledge among employees of HSS companies is high. Correlation and regression analysis, on the other hand, show that security training, staff involvement and policies promote significant relationship security. The role of safety knowledge as a mediator in the relationship between security management practices and safety performance can be concluded to have a significant impact. The role of employers needs to be more robust in enforcing rules and regulations to employees in HSS companies. Relationships between employers and employees also require tolerance and it will guarantee the achievement of company health and occupational safety goals. This research paper also discusses the findings of the study, the limitations of the study and recommendations for further study

Chemoenzymatic Asymmetric Synthesis of Complex Heterocycles: Dihydrobenzoxazinones and Dihydroquinoxalinones

Chiral dihydrobenzoxazinones and dihydroquinoxalinones serve as essential building blocks for pharmaceuticals and agrochemicals. Here, we report short chemoenzymatic synthesis routes for the facile preparation of these complex heterocycles in an optically pure form. These synthetic routes involve a highly stereoselective hydroamination step catalyzed by ethylenediamine-N,N′-disuccinic acid lyase (EDDS lyase). This enzyme is capable of catalyzing the asymmetric addition of various substituted 2-aminophenols to fumarate to give a broad range of substituted N-(2-hydroxyphenyl)-l-aspartic acids with excellent enantiomeric excess (ee up to >99%). This biocatalytic hydroamination step was combined with an acid-catalyzed esterification–cyclization sequence to convert the enzymatically generated noncanonical amino acids into the desired dihydrobenzoxazinones in good overall yield (up to 63%) and high optical purity (ee up to >99%). By means of a similar one-pot, two-step chemoenzymatic approach, enantioenriched dihydroquinoxalinones (ee up to >99%) were prepared in good overall yield (up to 78%) using water as solvent for both steps. These chemoenzymatic methodologies offer attractive alternative routes to challenging dihydrobenzoxazinones and dihydroquinoxalinones, starting from simple and commercially available achiral building blocks