A simple test improves checking satisfiability

AbstractIn many practical cases satisfiability of a set of clauses can be decided before an interpretation is found that satisfies all clauses of the set. We present a test for such an early discovery of satisfiability, EDS, and develop an algorithm, IDP, incorporating EDS and a branching heuristics related to this test. IDP was implemented and tested on a wide variety of instances and showed a high performance and stability with respect to changing the proportion of non-Horn clauses

Alternative formulas for synthetic dual system estimation in the 2000 census

The U.S. Census Bureau provides an estimate of the true population as a supplement to the basic census numbers. This estimate is constructed from data in a post-censal survey. The overall procedure is referred to as dual system estimation. Dual system estimation is designed to produce revised estimates at all levels of geography, via a synthetic estimation procedure. We design three alternative formulas for dual system estimation and investigate the differences in area estimates produced as a result of using those formulas. The primary target of this exercise is to better understand the nature of the homogeneity assumptions involved in dual system estimation and their consequences when used for the enumeration data that occurs in an actual large scale application like the Census. (Assumptions of this nature are sometimes collectively referred to as the ``synthetic assumption'' for dual system estimation.) The specific focus of our study is the treatment of the category of census counts referred to as imputations in dual system estimation. Our results show the degree to which varying treatment of these imputation counts can result in differences in population estimates for local areas such as states or counties.Comment: Published in at http://dx.doi.org/10.1214/193940307000000400 the IMS Collections (http://www.imstat.org/publications/imscollections.htm) by the Institute of Mathematical Statistics (http://www.imstat.org

Trace elements in Missouri soils

This bulletin is a report on Department of Agricultural Chemistry research project number 147, entitled 'Mineral Content of Missouri Grown Feeds'--P. [2].Digitized 2007 AES.Includes bibliographical references (pages 19-20)

A lower bound for tree resolution

AbstractIn this article, highly expanding degree-3 bipartite graphs are generated randomly. Every graph gives rise to a contradictory set of clauses, and these particular graphs provide us with a highly interconnected set of 3SAT clauses. If n is the number of nodes in each side of the graph, then there are 3n variables and 8n clauses. We use this set to prove a lower bound for tree resolution. The lower bound obtained is 2(23λn) where λ≈0.3166. Letter N = 3n be the number of variables, this bound is ≈ 2.070355N. This is contrasted with the best-known upper bound for 3SAT, from the algorithm in Monien and Speckenmeyer (1985), which is ≈ 2.6943N where again N is the number of variables. Exponential lower bounds have been proved for stronger forms of resolution, but with significantly smaller constants

Economic growth, innovation systems, and institutional change: a trilogy in five parts

Development and growth are products of the interplay and interaction among heterogeneous actors operating in specific institutional settings. There is a much alluded-to, but under-investigated, link between economic growth, innovation systems, and institutions. There is widespread agreement among most economists on the positive reinforcing link between innovation and growth. However, the importance of institutions as catalysts in this link has not been adequately examined. The concept of innovation systems has the potential to fill this gap. But these studies have not conducted in-depth institutional analyses or focussed on institutional transformation processes, thereby failing to link growth theory to the substantive institutional tradition in economics. In this paper we draw attention to the main shortcomings of orthodox and heterodox growth theories, some of which have been addressed by the more descriptive literature on innovation systems. Critical overviews of the literatures on growth and innovation systems are used as a foundation to propose a new perspective on the role of institutions and a framework for conducting institutional analysis using a multi-dimensional typology of institutions. The framework is then applied to cases of Taiwan and South Korea to highlight the instrumental role played by institutions in facilitating and curtailing economic development and growth

Measurement of bend sprinting kinematics with three-dimensional motion capture : a test-retest reliability study

Sprint velocity decreases on the bend when compared with the straight, therefore understanding technique during bend sprinting could have important implications for aiding race performance. Few bend sprinting studies have used optoelectronic cameras to investigate kinematic variables. Limited published evidence regarding the reliability of marker sets in conditions representative of elite bend sprinting makes model selection difficult. Therefore, a test-retest protocol was conducted to establish the reliability and minimum detectable difference of a lower limb and trunk marker set during bend sprinting (radius: 36.5 m). Six participants completed five, 60 m trials at maximum effort, with data collected at 38 - 45 m. This was repeated 2 - 7 days later. Spatio-temporal (e.g. contact time) and kinematic variables (e.g. peak joint angles) were evaluated. Intraclass correlation coefficients (ICC) were used to determine the between- and within-day reliability. Between-day reliability (ICC 3, k) was fair to excellent for all variables. Compared to between-day, within-day reliability demonstrated stronger agreement for the majority of variables. Thus, same-day data collection is preferable. It has been established that the marker set is reliable for future use. In addition, the minimal detectable difference was calculated which serves as useful reference for future research in bend sprinting

Empathy in the Middle-School History Classroom: The Effects of Reading Different Historical Texts on Theory of Mind, Empathic Concern, and Historical Perspective-Taking

Theoretical and empirical evidence indicate a possibility that reading certain types of historical texts could improve different constructs of empathy that include theory of mind (ToM), empathic concern (EC), and historical perspective-taking (HPT).The objective of this study was to compare the effect of reading a collection of primary documents in comparison to a historical narrative on ToM, HPT, and EC for adolescents in an eighth-grade history class. Students were randomly assigned to read either a historical narrative or a collection of adapted historical documents with approximately the same length, and reading level. This researcher controlled for student comprehension scores, ToM scores, estimated amount of reading frequency, gender, and age. Post reading, students were assessed on ToM, EC, and HPT using age-appropriate and valid measures. The results demonstrated no statistical difference for individuals assigned to read either text as measured by ToM, EC, and HPT. Individuals with higher comprehension abilities in the historical document group were more likely to read for a longer period of time than individuals with high comprehension abilities in the narrative group. Empathic emotions for the narrative group were significantly correlated with higher HPT. The researcher argues that better ToM assessments need to be developed for adolescents and the relationship of reading historical texts and empathy for adolescents should be a topic of future research

Connecting Schools and Communities: A Spatial Approach to Social Capital and Student Performance in the Albuquerque Public School District

Locating services and accesses to opportunities is a growing trend in community schools. Having on-site health services, employment programs, after-school programs, and other social services for students, parents, and members in a community surrounding a school, strengthens the relationships between schools and the communities they serve. These relationships foster increased stocks of social capital in a community and with parents, and the link between parental and community social capital and student performance is strong. In order to make the most of limited resources, schools and school districts implementing community school models must identify which services and accesses to opportunities help to increase student, parent, and school bonds and relationships, in order to best improve student learning and performance. For my study I have identified and examined certain social capital indicators existing in communities surrounding elementary schools in the Albuquerque Public School District and analyzed their relationship to student test scores measuring proficiency in math and reading. I have found there is strong evidence linking parent involvement and the welcoming nature of a school and subsequent student performance

Economic growth, innovation systems, and institutional change: A Trilogy in Five Parts

Development and growth are products of the interplay and interaction among heterogeneous actors operating in specific institutional settings. There is a much alluded-to, but under-investigated, link between economic growth, innovation systems, and institutions. There is widespread agreement among most economists on the positive reinforcing link between innovation and growth. However, the importance of institutions as catalysts in this link has not been adequately examined. The concept of innovation systems has the potential to fill this gap. But these studies have not conducted in-depth institutional analyses or focussed on institutional transformation processes, thereby failing to link growth theory to the substantive institutional tradition in economics. In this paper we draw attention to the main shortcomings of orthodox and heterodox growth theories, some of which have been addressed by the more descriptive literature on innovation systems. Critical overviews of the literatures on growth and innovation systems are used as a foundation to propose a new perspective on the role of institutions and a framework for conducting institutional analysis using a multi-dimensional typology of institutions. The framework is then applied to cases of Taiwan and South Korea to highlight the instrumental role played by institutions in facilitating and curtailing economic development and growth.economics of technology ;