Optimized many body potential for fcc metals

A formalism for optimized many body (OMB) potentials to describe the interatomic interactions in fcc metals is described. The OMB approach is based on the Tersoff potential, widely used to describe covalently bonded materials, and is closely related to the charge optimized many body (COMB) potential formalism for oxides. OMB extends to first nearest neighbors only, and employs a third-order Legendre polynomial to distinguish fcc and hcp structures, the strength of which can be adjusted to match the intrinsic stacking fault energy to arbitrary precision. The potential also predicts generalized stacking fault energy curves that are in very close agreement to the values determined from electronic-structure calculations. This potential is thus well-suited to investigating mechanical properties such as plastic deformation at the atomic scale.     

The computerized scoring algorithm for the autobiographical memory test: updates and extensions for analyzing memories of English-speaking adults

ABSTRACT

The Autobiographical Memory Test (AMT) has been central in psychopathological studies of memory dysfunctions, as reduced memory specificity or overgeneralised autobiographical memory has been recognised as a hallmark vulnerability for depression. In the AMT, participants are asked to generate specific memories in response to emotional cue words, and their responses are scored by human experts. Because the manual coding takes some time, particularly when analysing a large dataset, recent studies have proposed computerised scoring algorithms. These algorithms have been shown to reliably discriminate between specific and non-specific memories of English-speaking children and Dutch- and Japanese-speaking adults. The key limitation is that the algorithm is not developed for English-speaking adult memories, which may cover a wider range of vocabulary that the existing algorithm for English-speaking child memories cannot process correctly. In the present study, we trained a new support vector machine to score memories of English-speaking adults. In a performance test (predicting memory specificity against human expert coding), the adult-memory algorithm outperformed the child-memory variant. In another independent performance test, the adult-memory algorithm showed robust performances to score memories that were generated in response to a different set of cues. These results suggest that the adult-memory algorithm reliably scores memory specificity.     

Structural and functional information—an evolutionary approach to pragmatic information

The paper starts with a critics of the potential information which is related to the statistical entropy. In order to include the syntactic and semantic aspects of information, we propose a distinction between structural and functional information, instead. Structural information represents the structural determination of a system state, it measures the content of information, as given by the material structure. Functional information, on the other hand, represents the operational closure of the system, it could be e.g. an algorithm which activates and interprets the existing structural information.

From an evolutionary point of view, pragmatic information is generated by an interplay of structural and functional information. This leads to a new insight into the concept of pragmatic information, which is not an invariant of evolution, but must be steadily re‐generated.

The active role of information in a self‐organization process is demonstrated in a model of artificial agents. It is shown by means of computer simulations that the feedback of already existing information on the generation of new information performs analogies to the creation of a collective memory.     

On teaching computer ethics within a computer science department

The author has surveyed a quarter of the accredited undergraduate computer science programs in the United States. More than half of these programs offer a “social and ethical implications of computing” course taught by a computer science faculty member, and there appears to be a trend toward teaching ethics classes within computer science departments. Although the decision to create an “in house” computer ethics course may sometimes be a pragmatic response to pressure from the accreditation agency, this paper argues that teaching ethics within a computer science department can provide students and faculty members with numerous benefits. The paper lists topics that can be covered in a computer ethics course and offers some practical suggestions for making the course successful. An earlier version of this paper was presented at the 2005 conference, Ethics and Social Responsibility in Engineering and Technology, Linking Workplace Ethics and Education, co-hosted by Gonzaga University and Loyola Marymount University, Los Angeles, California, 9–10 June 2005.     

Teaching ethics and technology with <Emphasis Type="Italic">Agora</Emphasis>, an electronic tool

Courses on ethics and technology have become compulsory for many students at the three Dutch technical universities during the past few years. During this time, teachers have faced a number of didactic problems, which are partly due to a growing number of students. In order to deal with these challenges, teachers in ethics at the three technical universities in the Netherlands — in Delft, Eindhoven and Twente — have developed a web-based computer program called Agora (see www.ethicsandtechnology.com). This program enables students to exercise their ethical understanding and skills extensively. The program makes it possible for students to participate actively in moral reflection and reasoning, and to develop the moral competencies that are needed in their later professional practice. The developers of the program have tried to avoid two traps. Firstly, they rejected, from the outset, a cookbook style of dealing with ethical problems that applied ethics is often taken to be and, secondly, they wanted to design a flexible program that respects the student’s as well as the teacher’s creativity, and that tries to engage students in moral reflection. Agora meets these requirements. The program offers possibilities that extend beyond the requirements that are usually accepted for case-exercises in applied ethics, and that have been realised in several other computer models for teaching ethics. In this article, we describe the main considerations in the development of Agora and the features of the resulting program.     

An effective strategy for integrating ethics across the curriculum in engineering: An ABET 2000 challenge

This paper describes a one-day workshop format for introducing ethics into the engineering curriculum prepared at the University of Puerto Rico at Mayagüez (UPRM). It responds to the ethics criteria newly integrated into the accreditation process by the Accreditation Board of Engineering and Technology (ABET). It also employs an ethics across the curriculum (EAC) approach; engineers identify the ethical issues, write cases that dramatize these issues, and then develop exercises making use of these cases that are specially tailored to mainstream engineering classes.The different activities and strategies employed in this workshop are set forth. Specific references are made to the cases and exercises developed as a result of these workshops. The paper ends by summarizing the different assessments made of the workshop by addressing the following questions: how did it contribute to the overall ABET effort at UPRM; could other universities benefit from a similar activity; and how did the participants evaluate the workshop?     

Computer game playing in adolescence: Prevalence and demographic indicators

Computer game playing is a popular activity among adolescents yet there have been no systematic studies in the U.K. on its prevalence and its demographics. A questionnaire study was undertaken with 387 adolescents (12–16 years of age) to establish the time spent playing computer games, who they first started playing with, the reasons why they first started and why they play now and negative consequences of play. Results revealed that for many adolescents, home computer game playing can take up considerable time with 7% of the sample playing for at least 30 hours a week. Although there were no differences between males and females in who played computer games, it was established that males were found to play significantly more regularly than females.     

Utility of computerized case simulations in therapist training and evaluation

The present quasi-experimental study attempted to evaluate the utility of a set of three computer simulations for therapist training and evaluation by comparing psychology students from two universities at three training levels. The three groups consisted of junior and senior level undergraduates, first year graduate students, and third or fourth year graduate students. Analysis of outcome measures indicated subjects were generally accepting of computer simulation use for therapist training and evaluation and performance differences between the groups could be explained by group population differences. The results are discussed relative to the utility for computer simulations use for therapist training and evaluation.     

Using the simultaneous protocol to study equivalence class formation: the facilitating effects of nodal number and size of previously established equivalence classes

The emergence of equivalence classes in college students is unlikely when all baseline relations are trained concurrently and all probes for emergent relations are then introduced concurrently (the simultaneous protocol). This experiment showed how the number of nodes and the size of previously established equivalence classes enhanced the emergence of new equivalence classes under the simultaneous protocol. First, one-node three-, five-, or seven-member classes or three-node five- or seven-member classes were established with college students. A sixth group received no pretraining. Then, the simultaneous protocol was used to establish new three-node five-member equivalence classes with all students. The speed and variability with which the baseline relations were established in the simultaneous protocol were inverse functions of number of nodes in the previously established classes, but not of their size. The percentage of subjects who showed the emergence of new equivalence classes under the simultaneous protocol was a direct function of number of nodes and size of pretrained classes. The additional time spent for pretraining greatly reduced the total training time needed to produce individuals who showed the emergence of classes under the simultaneous protocol. The total time saved was a direct function of number of nodes and number of stimuli in the pretrained classes.     

Interhemispheric effects of simulated lesions in a neural model of single-word reading

A neural model consisting of paired cerebral hemispheric regions interacting via homotopic callosal connections was trained to generate pronunciations for 50 monosyllabic words. Lateralization of this task occurred readily when different underlying cortical asymmetries were present. Following simulated focal cortical lesions of systematically varied sizes, acute changes in the distribution of cortical activation were found to be most consistent with experimental data when interhemispheric interactions were assumed to be excitatory. During subsequent recovery, the contribution of the unlesioned hemispheric region to performance improvement was a function of both the amount of preexisting lateralization and the side and size of the lesion. These results are discussed in the context of unresolved issues concerning the mechanisms underlying language lateralization, the nature of interhemispheric interactions, and the role of the nondominant hemisphere in recovery from adult aphasia.