Indicators of School Crime and Safety: 2013

A joint effort by the Bureau of Justice Statistics and National Center for Education Statistics, this annual report examines crime occurring in schools and colleges. This report presents data on crime at school from the perspectives of students, teachers, principals, and the general population from an array of sources--the National Crime Victimization Survey, the School Crime Supplement to the National Crime Victimization Survey, the Youth Risk Behavior Survey, the School Survey on Crime and Safety, the School and Staffing Survey and the Campus Safety and Security Survey

CORA - a knowledge based system for the analysis of case control studies

Carrying out a statistical analysis the researcher is concerned with the problem of choosing an appropriate statistical technique from a large number of competing methods. Most common statistical software offer different methods for analysing the data without giving any support concerning the adequacy of a method for a particular data set. This paper outlines the main features of the computer system CORA which provides a statistical analysis of stratified contingency tables and additionally supports the researcher at the different steps of this analysis. Here, the support given by the system consists of two different aspects. On the one hand, the help system of CORA contains general information on the implemented statistical methods which can be obtained on request. On the other hand an advice tool recommends an adequate statistical method which depends on the actual empirical casecontrol data to be analysed. To build up the advice tool a set of rules being discovered by machine learning from simulation studies is integrated into the system CORA. The paper is written in English

STRUTEX: A prototype knowledge-based system for initially configuring a structure to support point loads in two dimensions

Only recently have engineers begun making use of Artificial Intelligence (AI) tools in the area of conceptual design. To continue filling this void in the design process, a prototype knowledge-based system, called STRUTEX has been developed to initially configure a structure to support point loads in two dimensions. This prototype was developed for testing the application of AI tools to conceptual design as opposed to being a testbed for new methods for improving structural analysis and optimization. This system combines numerical and symbolic processing by the computer with interactive problem solving aided by the vision of the user. How the system is constructed to interact with the user is described. Of special interest is the information flow between the knowledge base and the data base under control of the algorithmic main program. Examples of computed and refined structures are presented during the explanation of the system

Relational values, place attachment and ecological loss of elderly people in Zurich

The relationship between humans and nature is constantly evolving. As a result of increasing prosperity, the value of nature has changed for many people. Whereas it used to have mainly instrumental values, such as providing food and clean water, other values are becoming increasingly significant as prosperity increases. These include not only intrinsic values but also relational values. The present study examines precisely these relational values in the city of Zurich, which are specific to older people. These relational values are related to the concepts of ecological loss and place attachment and are analysed retrospectively over the different life phases of the elderly. The data corpus consists of thirteen interviews with participants who have lived in Zurich for at least fifteen years and are over 70 years old. This study applies an interplay of deductive and inductive interview strategies and is based on the qualitative research approach of problem-centred-interviews. The analysis shows that a dichotomy characterises the relationship between older people in Zurich and nature. One side is based on what nature offers to humans. Here, eudaemonic values are in the foreground. Nature is particularly important to the participants because it has a great influence on the quality of life, especially through its contribution to the wellbeing of the participants. Other values that characterise this side of the dichotomy emerge through the experienced ecological loss. Participants have been found to form place attachments prior to ecological loss. On the other side of the dichotomy, the participants' regrets about the damage humans have done to nature, a sense of personal responsibility, and wishes for nature are found. Furthermore, ecological loss and place attachment bring out values that the participants have regarding nature. According to the interviews, the importance of nature either remains constant or increases over different phases of life, but it never declines in importance. Additionally, the participants consistently linked nature with positive attributes. This thesis also demonstrates that one's upbringing can have an impact on the relationship with nature but that this influence does not need to be limited to what is learned from one's family. Throughout life, nature plays a variety of roles, but it is particularly valued for its ability to serve as a mediator in friendships and relationships

Indicators of School Crime and Safety: 2014

A joint effort by the Bureau of Justice Statistics and National Center for Education Statistics, this annual report examines crime occurring in schools and colleges. This report presents data on crime at school from the perspectives of students, teachers, principals, and the general population from an array of sources--the National Crime Victimization Survey, the School Crime Supplement to the National Crime Victimization Survey, the Youth Risk Behavior Survey, the School Survey on Crime and Safety, the Schools and Staffing Survey, EDFacts, and the Campus Safety and Security Survey. The report covers topics such as victimization, bullying, school conditions, fights, weapons, the presence of security staff at school, availability and student use of drugs and alcohol, student perceptions of personal safety at school, and criminal incidents at postsecondary institutions

Experimentelle Analyse zweier logik-basierter Lernverfahren

Ein entscheidendes Problem des logik-basierten Lernens liegt in der Grösse des Hypothesenraumes. Möglichkeiten der Einschränkung sind das heuristische Durchsuchen eines vollständigen Hypothesenraums (z.B. FOIL) oder das vollständige Durchsuchen eines eingeschränkten Hypothesenraums (z.B. RDT). Während die theoretische Analyse die Lernbarkeit untersucht, wollen wir durch einen experimentellen Vergleich von RDT und FOIL feststellen, wie sich die unterschiedlichen Einschränkungen des Suchraums in der Praxis auswirken. Für unsere Experimente haben wir zum einen den KRK-Sachbereich und ausserdem einen neu modellierten Sachbereich, die Wohnortwahl für Studenten, verwendet. The paper is written in German

Vibrational Analysis of Soloflex Whole Body Vibration Platform

A Soloflex Whole Body Vibration (WBV) Platform was tested for its frequency and magnitude of vibration at multiple settings on the supplied dial. An accelerometer was used to measure the vibrations on different points mapped across the platform. The motor attached to the board was also tested for its frequency using a high-speed camera. The amplitude measurements found from the accelerometer data was compared to the readings on the supplied control module to “calibrate” the platform for medical testing

Stroboscopic Interferometer for Measuring Mirror Vibrations

Stroboscopic interferometry is a technique for measuring the modes of vibration of mirrors that are lightweight and, therefore, unavoidably flexible. The technique was conceived especially for modal characterization of lightweight focusing mirror segments to be deployed in outer space; however, the technique can be applied to lightweight mirrors designed for use on Earth as well as the modal investigation of other optical and mechanical structures. To determine the modal structure of vibration of a mirror, it is necessary to excite the mirror by applying a force that varies periodically with time at a controllable frequency. The excitation can utilize sinusoidal, square, triangular, or even asynchronous waveforms. Because vibrational modes occur at specific resonant frequencies, it is necessary to perform synchronous measurements and sweep the frequency to locate the significant resonant modes. For a given mode it is possible to step the phase of data acquisition in order to capture the modal behavior over a single cycle of the resonant frequency. In order to measure interferometrically the vibrational response of the mirror at a given frequency, an interferometer must be suitably aligned with the mirror and adjustably phase-locked with the excitation signal. As in conventional stroboscopic photography, the basic idea in stroboscopic interferometry is to capture an image of the shape of a moving object (in this case, the vibrating mirror) at a specified instant of time in the vibration cycle. Adjusting the phase difference over a full cycle causes the interference fringes to vary over the full range of motion for the mode at the excitation frequency. The interference-fringe pattern is recorded as a function of the phase difference, and, from the resulting data, the surface shape of the mirror for the given mode is extracted. In addition to the interferometer and the mirror to be tested, the equipment needed for stroboscopic interferometry includes an arbitrary-function generator (that is, a signal generator), an oscilloscope, a trigger filter, and an advanced charge-coupled-device (CCD) camera. The optical components are positioned to form a pupil image of the mirror under test on the CCD chip, so that the interference pattern representative of the instantaneous mirror shape is imaged on the CCD chip