Posts Tagged ‘h-index’

Nanotechnology for medicine, geometric and atomic world view, objective measure for citations and research style!

November 12, 2008

Here are a few technical and academic links — three from PNAS and one from Arunn’s Unruled Notebook:

Nanotechnology for medicine: R H Austin and S-f Lim in PNAS:

The Sackler Colloquium entitled “Nanomaterials in Biology and Medicine: Promises and Perils” was held on April 10–11, 2007. We have been able to assemble a representative sampling of 17 of the invited talks ranging over the topics presented. Any new technology carries with it both a promise of transforming the way we do things and the possibility that there are unforeseen consequences. The papers collected here represent a cross-section of these issues. As an example, we present our own work on nano-upconversion phosphors as an example of this new class of nanomaterials with potential use in medicine and biology.

Geometric and atomic world views: A Bohr, B R Mottelson and O Ulfbeck:

The atomic world view is based on the notion that matter is built of elementary constituents called atoms, and quantum mechanics was created in the pursuit of this view with probabilistic events caused by atomic particles. This conception involves unresolved ambiguities linked to the notion of an elementary quantum of action. The resolution of these problems in quantum mechanics requires a new, geometric, world view, which recognizes the occurrence of events, clicks in counters, coming without a cause, referred to as fortuitous. The possibility of a rational theory of probabilities for such events is based on the assignment to the individual click of a proper value of an element of (flat) space–time symmetry. Thereby, the distributions of uncaused clicks can be endowed with a geometric content in terms of the irreducible representations of space–time symmetry. Through fortuity, space–time invariance itself thus acquires a hitherto unrecognized role. Departing from the norms of physical theory, the uncaused click is not a measurement of something, and the reality mirrored in the distributions is the geometry of space time itself, and not a property of an imagined object. The geometric world view involves only the dimensions of space and time, and the absence of an irreducible dimension of mass is seen as the result of the discovery of new physical phenomena. Accordingly Planck’s constant has no place in fundamental theory and is seen as a relic of dimensions that have become superfluous.

Objective measure of scientific impact: F Radicchi, S Fortunato, and C Castellano:

We study the distributions of citations received by a single publication within several disciplines, spanning broad areas of science. We show that the probability that an article is cited c times has large variations between different disciplines, but all distributions are rescaled on a universal curve when the relative indicator cf = c/c0 is considered, where c0 is the average number of citations per article for the discipline. In addition we show that the same universal behavior occurs when citation distributions of articles published in the same field, but in different years, are compared. These findings provide a strong validation of cf as an unbiased indicator for citation performance across disciplines and years. Based on this indicator, we introduce a generalization of the h index suitable for comparing scientists working in different fields.

Science: as individual pursuit and Empire building activity — Arunn in Unruled Notebook:

Individual or Empire? Should we remain individual scientists or should I forge or join a research group for pursuing research. This is not an age old question, if we reckon the time span of human thought and scientific inquiry.

Science, until recently, has been an individual pursuit. There are reasons in our history and her-story on how it became a group pursuit. Industrial revolution, academic institutions, World Wars, funding based research, scientists (and Science) migration, state-run funding agencies, peer review, Ph. D. degree, academic business models, tenure track, publish or perish, research grants, proposal based funding, funding based Science, post docs, research sans teaching professors, research empires, professors as research managers, quantity as quality, scientists as entrepreneurs, students as workers, the sequence is telling.

But Individuals remain. Why?

The b-index?

March 18, 2008

We all are aware of h-index; John Hawks brings to our attention another indicator of scientific output (which, for obvious reasons, I like to call the b-index, and is the number of beers somebody drinks per hour in a party):

According to the study, published in February in Oikos, a highly respected scientific journal, the more beer a scientist drinks, the less likely the scientist is to publish a paper or to have a paper cited by another researcher, a measure of a paper’s quality and importance.

Hawks also calls for action at the end of his post:

All right, good scientists and bad scientists alike, you know what we have to do: DESTROY THIS CORRELATION!

I’d love to–but I can’t! So, I think I will just stick with correlation does not imply causation.

Symmetry, shape and order, and the predictive powers of h-index

December 4, 2007

A couple of interesting papers in the latest issue of PNAS:

  • Symmetry, shape and order by Trovato et al:

    Packing problems have been of great interest in many diverse contexts for many centuries. The optimal packing of identical objects has been often invoked to understand the nature of low-temperature phases of matter. In celebrated work, Kepler conjectured that the densest packing of spheres is realized by stacking variants of the face-centered-cubic lattice and has a packing fraction of \pi/(3 \sqrt{2}) \approx 0.7405. Much more recently, an unusually high-density packing of \approx 0.770732 was achieved for congruent ellipsoids. Such studies are relevant for understanding the structure of crystals, glasses, the storage and jamming of granular materials, ceramics, and the assembly of viral capsid structures. Here, we carry out analytical studies of the stacking of close-packed planar layers of systems made up of truncated cones possessing uniaxial symmetry. We present examples of high-density packing whose order is characterized by a broken symmetry arising from the shape of the constituent objects. We find a biaxial arrangement of solid cones with a packing fraction of \pi/4. For truncated cones, there are two distinct regimes, characterized by different packing arrangements, depending on the ratio c of the base radii of the truncated cones with a transition at c^{\star} = \sqrt{2} - 1.

  • Does the h index have predictive power? by J E Hirsch:

    Bibliometric measures of individual scientific achievement are of particular interest if they can be used to predict future achievement. Here we report results of an empirical study of the predictive power of the h index compared with other indicators. Our findings indicate that the h index is better than other indicators considered (total citation count, citations per paper, and total paper count) in predicting future scientific achievement. We discuss reasons for the superiority of the h index.