126,731 research outputs found
On the computing power of +, -, and Ã
No full textModify the Blum-Shub-Smale model of computation replacing the permitted computational primitives (the real field operations) with any finite set B of real functions semialgebraic over the rationals. Consider the class of Boolean decision problems that can be solved in polynomial time in the new model by machines with no machine constants. How does this class depend on B? We prove that it is always contained in the class obtained for B = +,-, Ã. Moreover, if B is a set of continuous semialgebraic functions containing + and -, and such that arbitrarily small numbers can be computed using B, then we have the following dichotomy: either our class is P or it coincides with the class obtained for B = +,-, Ã. Copyright © 2014 ACM
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Surface second-harmonic generation from Si(111)(1 × 1)H: Theory versus experiment
No full textComparing calculations of the second-harmonic generation (SHG) from the monohydride-terminated Si(111)(1 × 1)H surface with experimental spectra covering the two-photon energy range from 2.4 eV to 5.0 eV, we present a quantitative test of available state-of-the-art theory of surface SHG from a well-characterized semiconductor surface. We conclude that the density-functional theory within the local-density approximation approach with quasiparticle corrections leads to a semiquantitative agreement between theory and experiment and that the SHG arises from transition across bulk states which are perturbed by the surface. The calculations show that the spectra are sensitive to relaxations of the second-layer Si atoms
Dispelling the Myths Behind First-author Citation Counts
No full textWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Perbedaan Representasi Sosial Tentang Siswa Junior antara Siswa Kelas XII SMAN A Dan SMAN B
No full textSeniority is a social phenomenon that is naturally found in the school environment. At SMAN A, seniority has been abused by senior students. Meanwhile, at SMAN B, seniority has been applied positively. This difference indicates that there were unique meanings given to the junior students by the seniors in the two schools. This study aims to understand these differences by using social representations theory with the structural approach. The study was conducted in two stages. Free association method was used in the first stage to discover the attributes of social representation of junior students. Researchers asked 206 participants at SMAN A and 198 participants at SMAN B to write down the things that came to mind when they read the word "junior students". The second stage aims to identify the attributes of the central core and peripherals. A total of 92 participants from SMAN A and 92 participants from SMAN B were asked to fill out a questionnaire. The data were analyzed with the centrality test and chi-square test. The results show 18 attributes of social representation of junior students. At SMAN A, attributes of central core are [1] charming appearance and [2] the orientation of students and attribute of peripherals are [1] negative behaviors, [2] the targets of mistreatment, [3] unique appearance, [4] peeve, [5] new students, and [6] paltry. At SMAN B, attributes of central core are [1] charming appearance, [2] the orientation of students, [3] good relationships, and [4] positive behaviors and attributes of peripherals are [1] cool, [2] need to be nurtured, [3] new students, and [4] different generations. This results show differences in social representation of junior students in twelfth-graders at SMAN A and SMAN B. This study suggests that SMAN A make innovation in school regarding to student activities by looking up to SMAN B
Waves of novelties in the expansion into the adjacent possible
No full textThe emergence of novelties and their rise and fall in popularity is an ubiquitous phenomenon in human activities. The coexistence of popular evergreens with novel and sometimes ephemeral trends pervades technological, scientific and artistic production. Though this phenomenon is very intuitively captured by our common sense, a comprehensive explanation of how waves of novelties are not hampered by well established old-comers is still lacking. Here we first quantify this phenomenology by empirically looking at different systems that display innovation at very different levels: the creation of hashtags in Twitter, the evolution of online code repositories, the creation of texts and the listening of songs on online platforms. In all these systems surprisingly similar patterns emerge as the non-trivial outcome of two contrasting forces: the tendency of retracing already explored avenues (exploit) and the inclination to explore new possibilities. These findings are naturally explained in the framework of the expansion of the adjacent possible, a recently introduced theoretical framework that postulates the restructuring of the space of possibilities conditional to the occurrence of innovations. The predictions of our theoretical framework are borne out in all the phenomenologies investigated, paving the way to a better understanding and control of innovation processes
Pragmatic Case Studies as a Source of Unity in Applied Psychology
No full textTo unify or not to unify applied psychology: that is the question. In this article we review pendulum swings in the historical efforts to answer this question—from a comprehensive, positivist, “top-down,” deductive yes between the 1930s and the early 60s, to a postmodern no since then. A rationale and proposal for a limited, “bottom-up,” inductive yes in applied psychology is then presented, employing a case-based paradigm that integrates both positivist and postmodern themes and components. This paradigm is labeled “pragmatic psychology” and, its specific use of case studies, the “Pragmatic Case Study Method” (“PCS Method”). We call for the creation of peer-reviewed journal-databases of pragmatic case studies as a foundational source of unifying applied knowledge in our discipline. As one example, the potential of the PCS Method for unifying different angles of theoretical regard is illustrated in an area of applied psychology, psychotherapy, via the case of Mrs. B. The article then turns to the broader historical and epistemological arguments for the unifying nature of the PCS Method in both applied and basic psychology.Peer reviewe
Dr. Edwin Wright Collection: Author Unknown
No full textNotes - The author relates several short stories about his neighbours including Alex McDonell, homesteading and life around Meanook and Athabasca (1 page
Appropriate Similarity Measures for Author Cocitation Analysis
No full textWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Use of distributed real-time simulations in ATM validation: Examples based on the analysis of controller – pilot interaction
No full textThis paper discusses how the use of distributed simulation setups has already helped validating specific concepts affecting the interaction between controllers and pilots. Coupling ATC- and flight simulation facilities provided the opportunity for a close look at the dynamic effects of new procedures and technologies on the human actors involved
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