SN 2005hj: Evidence for Two Classes of Normal-Bright SNe Ia and Implications for Cosmology

HET Optical spectra covering the evolution from about 6 days before to about 5 weeks after maximum light and the ROTSE-IIIb unfiltered light curve of the "Branch-normal" Type Ia Supernova SN 2005hj are presented. The host galaxy shows HII region lines at redshift of z=0.0574, which puts the peak unfiltered absolute magnitude at a somewhat over-luminous -19.6. The spectra show weak and narrow SiII lines, and for a period of at least 10 days beginning around maximum light these profiles do not change in width or depth and they indicate a constant expansion velocity of ~10,600 km/s. We analyzed the observations based on detailed radiation dynamical models in the literature. Whereas delayed detonation and deflagration models have been used to explain the majority of SNe Ia, they do not predict a long velocity plateau in the SiII minimum with an unvarying line profile. Pulsating delayed detonations and merger scenarios form shell-like density structures with properties mostly related to the mass of the shell, M_shell, and we discuss how these models may explain the observed SiII line evolution; however, these models are based on spherical calculations and other possibilities may exist. SN 2005hj is consistent with respect to the onset, duration, and velocity of the plateau, the peak luminosity and, within the uncertainties, with the intrinsic colors for models with M_shell=0.2 M_sun. Our analysis suggests a distinct class of events hidden within the Branch-normal SNe Ia. If the predicted relations between observables are confirmed, they may provide a way to separate these two groups. We discuss the implications of two distinct progenitor classes on cosmological studies employing SNe Ia, including possible differences in the peak luminosity to light curve width relation.Comment: ApJ accepted, 31 page

Discreet element modeling of under sleeper pads using a box test

It has recently been reported that under sleeper pads (USPs) could improve ballasted rail track by decreasing the sleeper settlement and reducing particle breakage. In order to find out what happens at the particle-pad interface, discrete element modelling (DEM) is used to provide micro mechanical insight. The same positive effects of USP are found in the DEM simulations. The evidence provided by DEM shows that application of a USP allows more particles to be in contact with the pad, and causes these particles to transfer a larger lateral load to the adjacent ballast but a smaller vertical load beneath the sleeper. This could be used to explain why the USP helps to reduce the track settlement. In terms of particle breakage, it is found that most breakage occurs at the particle-sleeper interface and along the main contact force chains between particles under the sleeper. The use of USPs could effectively reduce particle abrasion that occurs in both of these regions

Methodological issues in cross-cultural research

Regardless of whether the research goal is to establish cultural universals or to identify and explain cross-cultural differences, researchers need measures that are comparable across different cultures when conducting cross-cultural studies. In this chapter, we describe two major strategies for enhancing cross-cultural comparability. First, we discuss a priori methods to ensure the comparability of data in cross-cultural surveys. In particular, we review findings on cross-cultural differences based on the psychology of survey response and provide suggestions on how to deal with these cultural differences in the survey design stage. Second, we discuss post hoc methods to ascertain data comparability and enable comparisons in the presence of threats to equivalence

Parameter estimation in the classical occupancy model

Occupancy model, Population size estimation, Air sampling, Health surveillance system,

Managing knowledge and learning for process improvement: a software-mediated process assessment approach for IT service management

As business users increasingly rely upon services from their information technology (IT) service providers, the demand for process improvements in IT services will continue to grow. Although service outcome measures, such as customer satisfaction, may represent the desired end result of IT services, validated assessment of processes provides an important additional element to process improvement efforts, as they may determine actions that could be taken to improve IT services. In the fast-changing and dynamic business environment, IT service organisations must continue to improve their learning processes, create knowledge and implement best practices that allow them to be able to deliver innovative and adaptive value-adding services to their clients. In this chapter, we describe how we applied the software-mediated process assessment (SMPA) approach to assist IT service organisations to conduct process assessments in a transparent and cost-effective manner. In addition, we introduce a knowledge management (KM) process cycle that illustrates how KM and learning processes may be used concurrently to achieve process improvement within the SMPA approach for maximum impact in the IT service management (ITSM) sector. We introduce and discuss three innovative strategies using the SMPA approach to conduct process assessments in the ITSM sector. The practical strategies include (1) adopting the international standards for assessments; (2) facilitating assessments using a decision support system (DSS) tool; and (3) incorporating process assessments for managing knowledge and learning processes. A KM process cycle along with the SMPA approach is introduced. Key value propositions of the SMPA approach are highlighted