Segre decomposition of spacetimes

Following a recent work in which it is shown that a spacetime admitting Lie-group actions may be disjointly decomposed into a a closed subset with no interior plus a dense finite union of open sets in each of which the character and dimension of the group orbits as well as the Petrov type are constant, the aim of this work is to include the Segre types of the Ricci tensor (and hence of the Einstein tensor) into the decomposition. We also show how this type of decomposition can be carried out for any type of property of the spacetime depending on the existence of a continuous endomorphism.Comment: 15 pages, provisionally scheduled for April 1999 in Class. Quantum Gra

On closed subsets of non-commutative association schemes of rank 6

The notion of an association scheme is a generalization of the concept of a group. In fact, the so-called thin association schemes correspond in a well-understood way to groups. In this thesis, we look at the structure of non-commutative association schemes of rank 6. We will show that a non-normal closed subset of a noncommutative association scheme of rank 6, must have rank 2. The so-called Coxeter schemes of rank 6 which we present in Section 4 provide examples of association schemes of rank 6 with non-normal closed subsets of rank 2. It is shown that normal closed subsets of imprimitive non-commutative schemes of rank 6 must have rank 2 or 3, so we will also look at the structure of association schemes of rank 6, with symmetric normal closed subsets of rank 3, and the structure of association schemes of rank 6 when they have non-symmetric closed subsets of rank 3. We will additionally see how to construct an association scheme of rank 6 with non-symmetric normal closed subsets

The Bourbaki-Jacobson correspondence

A general ring theoretic correspondence between subrings of the endomorphism ring of the additive group of a commutative field will be established. This correspondence (called Bourbaki-Jacobson Correspondence) provides the ordinary Galois correspondence when applied to specific group rings. Throughout this thesis, we will work with finite dimensional field extensions

Sometimes an Impact Fee Is Not Just an Impact Fee: The Possible Inequitable Application of Hawaii\u27s Impact Fee Statute to Foreign Investors

Historically, Hawaii has assessed foreign developers high impact fees either as a means to raise capital for affordable housing or as a means to regulate foreign investment. In 1992, Hawaii enacted House Bill 3787, an impact fee statute, to promote uniformity in Hawaii\u27s assessments of impact fees. Although Hawaii\u27s statute provides uniformity for most developers, it still permits local governments to assess foreign developers disproportionately higher impact fees. This Comment examines how a foreign developer might challenge either Hawaii\u27s impact fee statute or an individual impact fee assessment as violating his or her constitutional rights under the Fourteenth Amendment\u27s Equal Protection Clause. This Comment further argues that assessing foreign developers high impact fees either as a means to pay for affordable housing or as a means to regulate foreign investment is a bad policy choice in light of Hawaii\u27s general need for investmen

NLO corrections to the gluon induced forward jet vertex from the high energy effective action

We determine both real and virtual next-to-leading order corrections to the gluon induced forward jet vertex, from the high energy effective action proposed by Lipatov. For these calculations we employ the same regularization and subtraction formalism developed in our previous work on the quark-initiated vertex. We find agreement with previous results in the literature.Comment: 16 page

El nuevo marco jurídico de la ciudad y el territorio

A partir de la Ley de suelo de 1956 comienza a configurarse en España el cuerpo normativo alrededor del concepto de urbanismo. Ya en la década de los noventa, será una legislación adaptada a la economía globla la que garantice, entre otros aspectos, el equilibrio y la colaboración interterritorial

Online Professional Development: Implications on Self-Efficacy Levels and Classroom Instruction for Teachers in a Catholic High School

Online professional development (online PD), the acquisition of new skills and knowledge related to the teaching profession via the Internet, is an emerging field for teachers. This mixedmethods research explored the impact of an online PD program on high school teachers’ selfefficacy levels, classroom instruction, and the role that school culture played on teachers accepting or rejecting the online PD. Within a social cognitive theory lens, this study helped frame teacher attitudes and adult learning in the context of school culture. Phase 1 of this study used quantitative data from two surveys called PRE and POST, which were taken before and after the online PD program, respectively. Qualitative data were collected in Phase 2, using the International Society for Technology in Education Classroom Observation Tool (ICOT), participants’ journal reflections, and interviews. Findings indicated statistically significant changes in self-efficacy levels for eight of the 21 survey items and minimal changes in technology use during instruction. Furthermore, various aspects of school culture independently affected teachers’ inclination to accept or reject the online PD. Findings supported the concept of designing personalized professional development programs tailored to the individual’s specific learning styles, attitudes, and experiences of school culture

Comparison of wearable measurement systems for estimating trunk postures in manual material handling, A

2017 Fall.Includes bibliographical references.Epidemiologic studies have established that awkward trunk postures during manual materials handling are associated with an increased risk of developing occupational low back disorders. With recent advances in motion capture technology, emerging wearable measurement systems have been designed to quantify trunk postures for exposure assessments. Wearable measurement systems integrate portable microelectromechanical sensors, real-time processing algorithms, and large memory capacity to effectively quantify trunk postures. Wearable measurement systems have been available primarily as research tools, but are now quickly becoming accessible to health and safety professionals for industrial application. Although some of these systems can be highly complex and deter health and safety professionals from using them, other systems can serve as a simpler, more user-friendly alternative. These simple wearable measurement systems are designed to be less intricate, allowing health and safety professionals to be more willing to utilize them in occupational posture assessments. Unfortunately, concerns regarding the comparability and agreement between simple and complex wearable measurement systems for estimating trunk postures are yet to be fully addressed. Furthermore, application of wearable measurement systems has been affected by the lack of adaptability of sensor placement to work around obstructive equipment and bulky gear workers often wear on the job. The aims of the present study were to 1) compare the Bioharness™3, a simple wearable measurement system, to Xsens™, a complex wearable measurement system, for estimating trunk postures during simulated manual material handling tasks and 2) to explore the effects of Xsens sensor placement on assessing trunk postures. Thirty participants wore the two systems simultaneously during simulated tasks in the laboratory that involved reaching, lifting, lowering, and pushing a load for ten minutes. Results indicated that the Bioharness 3 and Xsens systems are comparable for strictly estimating trunk postures that involved flexion and extension of 30° or less. Although limited to a short range of trunk postures, the Bioharness also exhibited moderate to strong agreement and correlations with the Xsens system for measuring key metrics commonly used in exposure assessments, including amplitude probability distribution functions and percent time spent in specific trunk posture categories or bins. The Bioharness is suggested to be an a more intuitive alternative to the Xsens system for posture analysis, but industrial use of the device should be warranted in the context of the exposure assessment goals. In addition, a single motion sensor from the Xsens system placed on the sternum yielded comparable and consistent estimates to a sensor secured on the sternum relative to a motion sensor on the sacrum. Estimates included descriptive measures of trunk flexion and extension and percent time spent in specific trunk posture categories. Using one motion sensor instead of two may serve as an alternative for sensor placement configuration in situations where worker portable equipment or personal preference prevents preferred sensor placement