Models

This paper describes the analysis of L-band radiometric measurement data gathered with the synthetic aperture radiometer HUT-2D during several ground-based and airborne measurement campaigns. The radiometric data are analyzed from the instrument's performance point of view, aiming to verify the theoretical performance of an instrument of this kind and to assess the performance of the HUT-2D radiometer system in particular. The data sets considered for the study consist of measurements of well-known natural targets, such as cosmic background radiation, and measurements of pure water scenes, the brightness temperature of which is possible to model based on in situ measurements. We define four figures of merit, which are applicable for synthetic aperture radiometers. These are radiometric resolution, image bias, pixel-to-pixel random error, and temporal stability. Then, we use the selected data sets to assess these in the case of HUT-2D. The experimental results are discussed and compared to the theoretical values, where applicable. Also, we discuss possibilities to improve the presented performance. The main results of this paper are the consolidated performance parameters of the HUT-2D instrument. We study and discuss the properties of the error components related to the technology in a general level, and study the scalability of the errors as a function of the measured targets. In particular, the stability of the direction-dependent error component is pointed out, and a mitigation guideline is proposed.

Abstract: This study elaborates the cultural categories of meanings used by seventh-graders at a junior high school to describe their teachers. It examines the common expressions students used in open-ended interviews to describe their teachers and their experience within these teachers' classes. A semantic structure that underlies the terms that students used to describe their teachers was conceptualized in the following form: the highest level of abstraction and generalizability were four foci (academic work, instructional facility, ...

This paper presents the results of ground vibration measurements carried out in Hisarcik Boron open pit mine located on the west side of central Anatolia near Kütahya province in Turkey. Within the scope of this study to predict peak particle velocity (PPV) level for this site, ground vibration components were measured for 304 shots during bench blasting. In blasting operations, ANFO (blasting agent), gelatin dynamite (priming), and delay electric detonators (firing) were used as explosives. Parameters of scaled distance (charge quantity per delay and the distance between the source and the station) were recorded carefully and the ground vibration components were measured for all blast events using two different types of vibration monitors (one White Mini-Seis and one Instantel Minimate Plus Model). The absolute distances between shot points and monitor stations were determined using GPS. The equation of square root scaled distance extensively used in the literature was taken into consideration for the prediction of PPV. Then, the data pairs of scaled distance and particle velocity obtained from the 565 event records were analyzed statistically. At the end of statistical evaluation of the data pairs, an empirical relation which gives 50% prediction line with a reasonable correlation coefficient was established between PPV and scaled distance.

Reducing overfishing and recovering overfished fish stocks is a challenging and important global problem. Rebuilding targets are essential ingredients for guiding overfished stocks to recovery. Having robust estimates of rebuilding targets is likely a necessary condition for effective long-term management of fishery resources. In this paper, we show how Bayesian model averaging can be applied to estimate rebuilding targets under alternative hypotheses about stock–recruitment dynamics. Using alternative hypotheses about stock–recruitment dynamics and environmental variation is important because using only a single hypothesis can lead to substantially different reference points and policy implications. The alternative hypotheses are augmented with prior information collected from meta-analyses of stock–recruitment data to construct a set of age-structured production models. We illustrate our approach using three overfished New England groundfish stocks. We fit alternative model likeli...

Previous qualitative studies show that when the formal organization of a school and patterns of informal interaction are aligned, faculty and leaders in a school are better able to coordinate instructional change. This article combines social network analysis with interview data to analyze how well the formal and informal aspects of a school’s social context are aligned. The focus is on two elementary schools engaged in initiatives aimed to use data to inform instructional decision making. The multimethod case study integrated findings from questionnaire and interview data. Data were collected over two years from case study schools. By fitting multilevel social selection models to longitudinal social network data collected from surveys, the authors estimated the relative influence of formal and informal processes on patterns of advice giving in each school. They used interview data to contextualize and corroborate findings. The social selection models they fit revealed distinct patt...

... School of Engineering Springfield, Massachussetts Drag Reduction and Wake Minimization on Marine Vehicles ,,P. ,3 1991 By: , Craig A. Hunter Pasquale Delore Walter M. Presz, Jr. Final Report Office of Naval Research Grant N0014-89-J-1883 00 July 1991 I I Page 2. Abstract ...

Based on a framework emphasizing the social nature of learning, this research examines a model of how social constructs affect satisfaction within online learning using path analysis for students in higher education. The social constructs evaluated in this study include sense of community (SOC), social ability (SA), perceived ease of use (PEU) and usefulness (PU) of social awareness tools, and self-reported participation (SRP) in online courses. Students' social ability is predicted by perceived ease of use of social awareness ...

This paper describes the development of a methodology to import key products of the DoD Architecture Framework into an executable form to conduct a dynamic analysis of the Command and Control (C2) system or capability represented by the architecture. Dynamic analysis of these models enables a user to assess the impact of change and determine measures of performance and effectiveness. The research team successfully implemented the methodology in a demonstration that made a three-way link among a business process model, a communications network model, and a combat simulation representing the system's operational environment. We linked these models together via the Runtime Infrastructure (RTI) of the High Level Architecture (HLA). Basic HLA interactions that we established allowed key events in the combat simulation to initiate one or more business processes in the process model. As a business process proceeded in time, the process model requested from the communications model a de...

Over the past several years, increased interest in preventing youth problems and promoting healthy youth development has led youth and family practitioners, policy makers, and researchers to develop a wide range of approaches based on various theoretical frameworks. Although the growth in guiding frameworks has led to more complex models and a greater diversity in the options available to scholars and practitioners, the lack of an integrative conceptual scheme and consistent terminology has led to some confusion in the field. Here, we provide an overview of three approaches to youth development and problem prevention, critically examine their strengths and weaknesses, and offer some elaborations to help clarify, extend, and integrate the models. We conclude by discussing some general implications for researchers, practitioners, and policy makers. I n recent years, efforts to address youth problems and enhance youth development have become increasingly more broad-based, involving fam...

This study was an investigation of reading and spelling errors of dyslexic Arabic readers (n 1⁄4 20) compared with two groups of normal readers: a young readers group, matched with the dyslexics by reading level (n 1⁄4 20) and an age-matched group (n 1⁄4 20). They were tested on reading and spelling of texts, isolated words and pseudowords. Two research questions were the focus of this study: What are the reading and spelling profile errors of dyslexic native Arabic speakers? What is the effect of the Arabic orthography on these types of errors? The results of the reading error analysis revealed a clear contribution of the uniqueness of the Arabic orthography to the types of errors made by the three different groups. In addition, the error profiles of the dyslexic readers were similar to the error profiles made by the younger readinglevel-matched group in percentages and in quality. The most prominent types of errors were morphological and semiphonetic, which highlighted the contrib...