bluuebunny/crossref_metadata_2025 huggingface dataset:
Do College Students Benefit from High School Laboratory Courses?
Authors: Brown Sanborn C.
Published: August 2005

An extensive study was made to determine the effect of high school laboratory courses on freshman laboratory performance at MIT. Almost no significant effect was measured. It is concluded that the intellectual stimulation of laboratory education at the high school level is its basic contribution.
Chicago Public Schools Television Instruction Experiment in High School Physics
Authors: Engelhart Max D. , Schwachtgen Edward C. , Nee Mary M.
Published: August 2005

This is a report of the large scale controlled experimentation with televised high school physics instruction conducted last year in the Chicago Public Schools. It is especially significant in its critical evaluation of this new technique on the basis of data revealing the comparative achievements of students of differing levels of ability.
New Era in Science?
Authors: Buchta J. W.
Published: August 2005

In the years just ahead science may take an enhanced part in our Western society but caution is recommended lest science be submerged by and confused with technology, dominated by and its future determined by the military or other Federal Agencies with assigned practical goals. The role of the educational institutions in advancing science and the unique functions of these institutions in the preparation of the youth must not be degraded.
Acoustic Behavior of a Rubber String
Authors: Freeman Ira M.
Published: August 2005

The fundamental transverse vibration frequency of a rubber string remains almost constant when the string is stretched to greater lengths, in sharp contrast with the behavior of a nearly inextensible string. Using the known elastic properties of rubber, the results of the analysis are found to agree quantitatively with experiment.
Mnemonic Device for Relativistic Particle Kinematics
Authors: Crawford Frank S.
Published: August 2005

Several of the formulas encountered most frequently in relativistic particle kinematics problems are written in a form that exhibits clearly the transition between the nonrelativistic and extremely relativistic limits. The exact relativistic formulas in this form are related to the usual nonrelativistic formulas by the mnemonic device, “To the rest energy of each moving particle add one-half of the total c.m. system kinetic energy.” The exact relativistic formulas in this form are well suited to rapid slide-rule calculation; and the problem of “disappearing significant figures,” which ordinarily forces one to use a calculating machine to obtain final slide-rule accuracy, is automatically avoided. Also avoided are radicals with troublesome plus or minus signs. Numerical examples are given for each formula.
Experiment for Measuring the Coefficient of Restitution
Authors: Van Name F. W.
Published: August 2005

An intermediate mechanics experiment is described in which the coefficient of restitution is determined from measurements on the oblique impact between two spheres. A typical set of data is presented.
On the Use of the Notion “Probability” in Physics
Authors: Ehrenfest-Afanassjewa T.
Published: August 2005

An analysis of the meanings of such terms as “at random,” “equal chances,” “probability calculus,” “laws of probability” as used in physics. The author treated this subject for the first time in a lecture at St. Petersburg in 1911, after which it was published in Russian in the Journal of the Physical-Chemical Association of St. Petersburg. Later, Paul Ehrenfest made it the topic of several lectures.
Isotopic Spin
Authors: Davidson J. P.
Published: August 2005

The isotopic (or isobaric) spin formalism, so important in nuclear structure and meson problems, is developed. After a short introduction the Pauli theory of mechanical spin is reviewed and then this formalism is used to develop the isotopic spin formalism along parallel lines. Finally, some examples of the formalism's applications to beta decay and nuclear reaction problems are given.
μ
Meson and the Catalysis of Nuclear Reactions
Authors: D'Angelo N.
Published: August 2005

A summary is given of the few experimental and theoretical studies of μ mesons as catalyzers of nuclear reactions between hydrogen isotopes. Present indications are that this is not likely to be practical for the production of power.
Gravitational Field of a Point Charge
Authors: Callaway Joseph
Published: August 2005

A semiclassical derivation of the gravitational potential of a point charge is given. The result agrees with the general theory of relativity except for a factor of 12, which arises as a consequence of the vanishing of the trace of the electromagnetic stress-energy tensor.
New Look at the Theory of Electron-Phonon Resonance. II
Authors: Band William
Published: August 2005

The perturbation theory of the transitions between electron-phonon resonance states, developed in Part I, is here generalized to the many-electron problem, and applied to a discussion of the electrical conductivity of a linear lattice. The significance of the work for an understanding of superconductivity is also briefly discussed.
Integral Equations for the Schrödinger Wave Function
Authors: Tobocman W. , Foldy L. L.
Published: August 2005

For many problems in quantum mechanics it proves to be useful to write the Schrödinger equation as an integral equation rather than as a differential equation. In this paper we describe how the transformation of the Schrödinger equation from differential form to integral form may be accomplished. Two methods are described, one appropriate to bound-state theory and one appropriate to scattering theory. It is shown that the bound-state wave function is also a solution of the integral equation (Lippman-Schwinger equation) appropriate to scattering theory.
Motion of Free Particles in Discontinuous Gravitational Fields
Authors: Møller C.
Published: August 2005

A new paradox occurring in the usual solution of the original “clock paradox” is given a natural physical interpretation by the observation that the mass of a particle moving in a gravitational field depends on the gravitational potential as well as on the velocity, thus changing abruptly when a gravitational field is suddenly turned off.
Theory of Beams Composed of Two Elastic Materials
Authors: Simon A. W.
Published: August 2005

The theory involved in locating the neutral axis of a beam composed of two elastic materials (composite beam) is given. It is shown that the resulting flexural rigidity of such a beam is equal to the sum of the flexural rigidities of its parts. With these two factors, the tensile strain, tensile stress, slope, and deflection of the beam can be calculated from the usual formula. The shear stress is also calculated.
Physics Laboratory Administration and Operation
Authors: Strandberg M. W. P.
Published: August 2005

Laboratory instruction in undergraduate courses allows the student to encounter physical problems in association with physicists. The value of this experience does not derive from the experiments per se, but the administration and operation of the laboratory may be arranged to optimize its educational value.
Electromagnetic Equations in Generalized Units
Authors: Trigg George L.
Published: August 2005

The work of Berreman is extended by making the equations valid in the Gaussian and Heaviside-Lorentz systems and by adding other relations of importance or interest.
Note on Stress Effects due to Relativistic Contraction
Authors: Dewan E. , Beran M.
Published: August 2005

In this note a thought experiment will be used to show that relativistic contraction can introduce stress effects in a moving body.
The Interaction of π Mesons with Atomic Nuclei
Authors: Francis Norman C. , Watson Kenneth M.
Published: August 2005

The interactions of π mesons with nuclei are reviewed and interpreted in terms of the Serber model of nuclear reactions at high energies. This involves introducing the concept of a mean free path for both meson scattering and absorption in nuclear matter. These quantities are discussed in relation to the relevant experimental data. A discussion of the “optical model” of nuclear scattering is also included.
The cgs Units of Magnetic Susceptibility and Specific Magnetization
Authors: Cohn Ernst M. , Mentser Morris
Published: August 2005

The units of susceptibility and magnetization can be chosen so that they are identical in the (unrationalized) 3- and 4-dimensional cgs systems. These units and the defining equations are given, and inconsistencies in the literature are pointed out. Adoption of the present definitions would eliminate much existing confusion and satisfy the various schools of thought.
Energy Flow for a Variable-Gap Capacitor
Authors: Greene Nathaniel R.
Published: August 2005

When capacitor plates are separated, the capacitor's electrostatic energy either increases or decreases, depending upon whether the charge or the voltage is held constant. For the constant-voltage case, an interesting puzzle can be posed to students: How is it possible that an external agent does positive work on the capacitor while at the same time the capacitor's stored energy decreases? An energy flow diagram, as suggested by Art Hobson's TPT article,1 helps to visualize the movements of energy among different parts of the system. What Richard Feynman calls a “surprising factor of one-half” in the expression for the force between capacitor plates confronts students with an additional puzzle to decipher.2
A Simple, Inexpensive Chamber for Growing Snow Crystals in the Classroom
Authors: Hiramatsu Kazuhiko , Sturm Matthew
Published: August 2005

The creation of artificial snow crystals for scientific study usually requires patience, hard work, and fairly elaborate and expensive equipment that almost always includes a cold room. Here we describe an inexpensive and easy-to-build apparatus that can produce artificial snow crystals in the classroom. The apparatus, which can operate as both a diffusion and cloud chamber, was developed in Japan in 1996 and has been in use in schools there for several years, where it has also been reported on in scientific journals, the newspapers, and television.1,2 The apparatus allows students and teachers to actually watch snow crystals grow. While it has been demonstrated in the United States,3 we are not aware that it has seen much use here.
The Anharmonic Rotating Wheel
Authors: Carrau Juan F. , De Franco Vinícius Cappellano , Andreazza Marcos L. , Giovannini Odilon , Perottoni Cláudio A.
Published: August 2005

This paper describes the oscillatory motion of a mass suspended vertically at the end of a string that is attached to the axle of a wheel. The analysis of the motion is similar to that employed in the study of the Maxwell wheel.1 The time dependence of the displacement of the mass is determined using a PASCO motion sensor and compared with theoretical predictions. The moment of inertia of the wheel and the frictional torque acting on it are determined by fitting the theoretical function to the experimental data.
Coefficient of Restitution Measurements for Sport Balls: An Investigative Approach
Authors: Maynes K. C. , Compton M. G. , Baker Blane
Published: August 2005

Studies of collisions in the introductory laboratory often use carts moving on air tracks or along dynamics tracks. As an alternative, students in our laboratories study collisions through experiments that determine coefficients of restitution ε's of balls used in sport. Since ε's are crucial to the outcome of many sporting events, such activities provide students with a “real-world” context for studying collisions. In the process of investigation and analysis, students learn about inelastic collisions, energy transfer, and elasticity of materials.
Magnetic Field Viewing Cards
Authors: Kanim Stephen , Thompson John R.
Published: August 2005

For some years now laminated cards containing a green, magnetically sensitive film have been available from science education suppliers. When held near a magnet, these cards appear dark green in regions where the field is perpendicular to the card and light green where the field is parallel to the card. The cards can be used to explore the magnetic field near a variety of magnets as well as near wire loops. In this paper we describe how to make these cards and how we have used them in our physics classrooms and labs.
Toy Blocks and Rotational Physics
Authors: Varieschi Gabriele U. , Jully Isabel R.
Published: August 2005

Have you ever observed a child playing with toy blocks? A favorite game is to build towers and then make them topple like falling trees. To the eye of a trained physicist this should immediately look like an example of the physics of “falling chimneys,” when tall structures bend and break in mid-air while falling to the ground. The game played with toy blocks can actually reproduce well what is usually seen in photographs of falling towers, such as the one that appeared on the cover of the September 1976 issue of The Physics Teacher.1 In this paper we describe how we performed and analyzed these simple but interesting experiments with toy blocks.
An Alternative Approach to “Measuring Horsepower and Torque Curves of a Car”
Authors: Graney Chris M.
Published: August 2005

The article in the September 2003 issue of TPT by John Ross Buschert of Goshen College entitled “Measuring Horsepower and Torque Curves of a Car” was excellent.1 I attained similar results using existing automobile test data. Automobile performance tests done by magazines such as Road & Track are a treasure trove of good-quality physics data. Performance tests often contain all the data needed to replicate Professor Buschert's analysis of the power and torque output of automobile engines.
Moving Sources: Doppler Beats and Mach Cones
Authors: Gluck Paul
Published: August 2005

This paper describes two experiments involving moving sources. The first one is a class activity for observing beats in a Doppler setup; the second one describes how to observe the transition from “subsonic” to “supersonic” waves in a ripple tank.
It's About Time:Mark Twain's “My Watch” and Relativity
Authors: Henderson Hugh
Published: August 2005

Over three decades before Einstein's year of miracles, the American humorist Mark Twain published an essay titled “My Watch,”1 in which he recounts his experiences with a previously reliable pocket watch and those who tried to rehabilitate it. He begins his essay by confessing his first error: My beautiful new watch had run eighteen months without losing or gaining, and without breaking any part of its machinery or stopping. I had come to believe it infallible in its judgments about the time of day, and to consider its constitution and its anatomy imperishable. But at last, one night, I let it run down. I grieved about it as if it were a recognized messenger and forerunner of calamity.

Twain then sets the watch by guess, and takes it to the “chief jeweler's to set it by the exact time.” To Twain's dismay, the jeweler insists on opening it up and adjusting the regulator inside the watch, and the watch begins to gain time. It gained faster and faster day by day. Within a week it sickened to a raging fever, and its pulse went up to a hundred and fifty in the shade. At the end of two months, it had left all the timepieces of the town far in the rear, and was a fraction over thirteen days ahead of the almanac. It was away into November enjoying the snow, while the October leaves were still turning. It hurried up house rent, bills payable, and such things, in such a ruinous way that I could not abide it.
Measuring End Correction for a Quarter-Wave Tube
Authors: LoPresto Michael C.
Published: August 2005

The values for the speed of sound calculated in a standard quarter-wave tube experiment are generally too low because the measured length of the air-column is less than one-quarter of the wavelength of the sound. This is because the antinode of the standing wave generated by the tuning fork is in reality beyond the actual end of the tube. This error can be reduced by adding a standard “end correction” to the air-column length, generally considered to be about one-third the diameter of the tube.
An Inexpensive Moment of Inertia Experiment
Authors: Banks Peter E.
Published: August 2005

I am always looking for inexpensive and effective equipment that can be used for lab work. I use this experiment in my AP class when we study rotational motion. The objective is for students to compare an experimental value for the moment of inertia of a rotating system with a theoretical value. The setup is an adaptation of the equipment described in an article in the September 1994 issue of The Physics Teacher.1
Save Time with a High-Performance Grading System
Authors: Slater Timothy F.
Published: August 2005

Tim Slater is an associate professor of astronomy at the University of Arizona, where he directs the Science and Mathematics Education Center and conducts research on teaching and learning of Earth and space science. Tim's contributions to this column have proven valuable for physics teachers at both high school and university levels. Here he shares some time-saving tips that will help the busy teacher give students valuable feedback.
RUNNING OF THE SPECTRAL INDEX IN NONCOMMUTATIVE INFLATION
Authors: ALAVI S. A. , NASSERI FOROUGH
Published: August 2005

We study the cosmological implications of the space–space noncommutative inflation and present formulae for the spectral index and its running. Our results show that deviations from the spectral index and its running depend on the space–space noncommutativity length scale. We conclude that in the slow-roll regime of a typical inflationary scenario, space–space noncommutativity has negligible effects on both the spectral index and its running. Two classes of examples have been studied and comparisons made with the standard slow-roll formulae. The results show that the correction terms to the commutative case are positive for the spectral index and negative for the running of the spectral index. Nevertheless the spectral index in noncommutative spaces is less than one owing to the very small values of the correction terms.
LIOUVILLE THEORY AND LOGARITHMIC SOLUTIONS TO KNIZHNIK–ZAMOLODCHIKOV EQUATION
Authors: GIRIBET GASTÓN , SIMEONE CLAUDIO
Published: August 2005

We study a class of solutions to the SL (2, ℝ)k Knizhnik–Zamolodchikov equation.

First, logarithmic solutions which represent four-point correlation functions describing string scattering processes on three-dimensional anti-de Sitter space are discussed. These solutions satisfy the factorization ansatz and include logarithmic dependence on the SL (2, ℝ)-isospin variables. Different types of logarithmic singularities arising are classified and the interpretation of these is discussed. The logarithms found here fit into the usual pattern of the structure of four-point function of other examples of AdS/CFT correspondence. Composite states arising in the intermediate channels can be identified as the phenomena responsible for the appearance of such singularities in the four-point correlation functions. In addition, logarithmic solutions which are related to nonperturbative (finite k) effects are found.

By means of the relation existing between four-point functions in Wess–Zumino–Novikov–Witten model formulated on SL (2, ℝ) and certain five-point functions in Liouville quantum conformal field theory, we show how the reflection symmetry of Liouville theory induces particular ℤ2 symmetry transformations on the WZNW correlators. This observation allows to find relations between different logarithmic solutions. This Liouville description also provides a natural explanation for the appearance of the logarithmic singularities in terms of the operator product expansion between degenerate and puncture fields.
SCALAR FIELD THEORY ON κ-MINKOWSKI SPACE–TIME AND DOUBLY SPECIAL RELATIVITY
Authors: DASZKIEWICZ M. , IMIŁKOWSKA K. , KOWALSKI-GLIKMAN J. , NOWAK S.
Published: August 2005

In this paper we recall the construction of scalar field action on κ-Minkowski space–time and investigate its properties. In particular we show how the coproduct of κ-Poincaré algebra of symmetries arises from the analysis of the symmetries of the action, expressed in terms of Fourier transformed fields. We also derive the action on commuting space–time, equivalent to the original one. Adding the self-interaction Φ4 term we investigate the modified conservation laws. We show that the local interactions on κ-Minkowski space–time give rise to six inequivalent ways in which energy and momentum can be conserved at four-point vertex. We discuss the relevance of these results for Doubly Special Relativity.
ON THE GAUGE/GRAVITY CORRESPONDENCE AND THE OPEN/CLOSED STRING DUALITY
Authors: DI VECCHIA PAOLO , LICCARDO ANTONELLA , MAROTTA RAFFAELE , PEZZELLA FRANCO
Published: August 2005

In this paper we review the conditions for the validity of the gauge/gravity correspondence in both supersymmetric and nonsupersymmetric string models. We start by reminding what happens in type IIB theory on the orbifolds ℂ2/ℤ2and ℂ3/(ℤ2x ℤ2), where this correspondence beautifully works. In these cases, by performing a complete stringy calculation of the interaction among D3-branes, it has been shown that the fact that this correspondence works is a consequence of the open/closed duality and of the absence of threshold corrections. Then we review the construction of type 0 theories with their orbifolds and orientifolds having spectra free from both open and closed string tachyons and for such models we study the validity of the gauge/gravity correspondence, concluding that this is not a peculiarity of supersymmetric theories, but it may work also for nonsupersymmetric models. Also in these cases, when it works, it is again a consequence of the open/closed string duality and of vanishing threshold corrections.
CHIRAL ANOMALIES VIA CLASSICAL AND QUANTUM FUNCTIONAL METHODS
Authors: GOZZI E. , MAURO D. , SILVESTRI A.
Published: August 2005

In the quantum path integral formulation of a field theory model an anomaly arises when the functional measure is not invariant under a symmetry transformation of the Lagrangian. In this paper, generalizing previous work done on the point particle, we show that even at the classical level we can give a path integral formulation for any field theory model. Since classical mechanics cannot be affected by anomalies, the measure of the classical path integral of a field theory must be invariant under the symmetry. The classical path integral measure contains the fields of the quantum one plus some extra auxiliary ones. So, at the classical level, there must be a sort of "cancellation" of the quantum anomaly between the original fields and the auxiliary ones. In this paper we prove in detail how this occurs for the chiral anomaly.
SOME ALGEBRAICAL, COMBINATORIAL AND ANALYTICAL PROPERTIES OF PARAGRASSMANN VARIABLES
Authors: SCHORK MATTHIAS
Published: August 2005

Some algebraical, combinatorial and analytical aspects of paragrassmann variables are discussed. In particular, the similarity of the combinatorics involved with those of generalized exclusion statistics (Gentile's intermediate statistics) is stressed. It is shown that the dimensions of the algebras of generalized grassmann variables are related to generalized Fibonacci numbers. On the analytical side, some of the simplest differential equations are discussed and a suitably generalized Berezin integral as well as an associated delta-function are considered. Some remarks concerning a geometrical interpretation of recent results about fractional superconformal transformations involving generalized grassmann variables are given. Finally, a quantity related to the Witten index is discussed.
ENCODING THE SCALING OF THE COSMOLOGICAL VARIABLES WITH THE EULER BETA FUNCTION
Authors: PER M. A. , SEGUÍ A. J.
Published: August 2005

We study the scaling exponents for the expanding isotropic flat cosmological models. The dimension of space, the equation of state of the cosmic fluid and the scaling exponent for a physical variable are related by the Euler Beta function that controls the singular behavior of the global integrals. We encounter dual cosmological scenarios using the properties of the Beta function. When we study the integral of the density of entropy we reproduce the Fischler–Susskind holographic bound.
CRITICAL MAGNETIC FIELD IN CeCoIn5 SUPERCONDUCTOR
Authors: KOO JE HUAN , GILL DOH-HYUN , CHO GUANGSUP
Published: August 2005

We investigate the superconducting transition temperature, Tc in the presence of the magnetic field, H in CeCoIn 5. It is shown that phonon-enhanced spin fluctuations drive this superconductivity once more as suggested by us (Phys. Rev.B61, 4289). We know the magnetic dependence of our transition temperature is in good correspondence with experimental data. It is elucidated that the Fulde–Ferrell–Larkin–Ovchinnikov (FFLO) superconducting states are closely related to the temperature gradient contributed by the external magnetic field.
EFFECTS OF INTERFACIAL PSEUDO-SPIN COUPLING FLUCTUATIONS ON THE DIELECTRIC PROPERTIES OF FERROELECTRIC SUPERLATTICES
Authors: WU YIN-ZHONG , ZHANG WEI-MIN , SHEN MING-RONG , LI ZHEN-YA
Published: August 2005

Using effective-field theory with correlations, we investigate the effects of interfacial pseudo-spin coupling fluctuations on the susceptibility and polarization of ferroelectric superlattices within the framework of transverse Ising model. It is found that the interfacial coupling fluctuations increase the susceptibility in the low temperature region. For a strong interfacial coupling, the phase transition temperature decreases with the strength of fluctuations of the interfacial coupling. The dependence of the susceptibility on the superlattice period of BaTiO 3/ SrTiO 3 are plotted for different interfacial coupling fluctuations strength. At room temperature, when the interfacial coupling fluctuation increases, the peak position of the susceptibility will shift to a large superlattice period.
EFFECTS OF HEAT TREATMENT ON BLUE SAPPHIRES AS MONITORED BY ESR SPECTROSCOPY
Authors: UDOMKAN N. , LIMSUWAN P. , WINOTAI P. , MEEJOO S.
Published: August 2005

We report effects of heat treatments on physical properties and finding optimal heating condition to add value to Thai blue sapphires. The color of sapphire arises from the presence of trace 3d-transition ions in its crystal lattice. For blue sapphire, the color is due to a charge transfer mechanism between Fe 2+ and Ti 4+ ions. However, iron may adopt both Fe 3+ and Fe 2+ due to oxygen vacancies. Fe 3+ and Fe 2+ yield sapphire yellow and green colors, respectively. Therefore, we have to convert as many as possible of Fe 3+ to Fe 2+ by heating the blue sapphire in N 2 atmosphere for 12 h. Experimental results reveal that the ratio of lattice parameter c/a increases with the heating temperature and reaches maximum at 1700°C, which can be caused by displacement of Fe 3+ ions or more Fe 3+ ions being converted to Fe 2+. ESR signals show that the number of Fe 3+ ions decreases roughly linearly with the heating temperature. The intense sky blue color was achieved after the 1500°C heat treatment, having the [Formula: see text] ratio ~0.78. The optimal heat treatment should therefore be at 1500°C in flowing N 2 atmosphere for Thai blue sapphires which yield intense sky blue color and good crystal clarity. The blue sapphires exhibited good clarity but light sky blue due to the increase in lightness after the treatment at 1700°C. A monoclinic distortion of the corundum structure has been found to start at the 1600°C treatment by ESR spectrometer. This is also clearly evident from low angle shifts of XRD peaks after heating at 1700°C. We can therefore conclude that the color change of Thai blue sapphires arises from the conversion of Fe 3+ to Fe 2+ and thus the change in crystal field. The monoclinic distortion of the crystal structure may also play an important role in coloring the sapphires after the heat treatment at 1600–1700°C.
QUALITY MESHING OF POLYHEDRA WITH SMALL ANGLES
Authors: CHENG SIU-WING , DEY TAMAL K. , RAMOS EDGAR A. , RAY TATHAGATA
Published: August 2005

We present an algorithm to compute a Delaunay mesh conforming to a polyhedron possibly with small input angles. The radius-edge ratio of most output tetrahedra are bounded by a constant, except possibly those that are provably close to small angles. Furthermore, the mesh is not unnecessarily dense in the sense that the edge lengths are at least a constant fraction of the local feature sizes at the edge endpoints. This algorithm is simple to implement as it eliminates most of the computation of local feature sizes and explicit protective zones. Our experimental results validate that few skinny tetrahedra remain and they lie close to small acute input angles.
ANALYSIS OF THE DISPLACEMENT IN FRACTAL LATTICES WITH DIFFERENT NUMBER OF GRIDS
Authors: BABADAGLI TAYFUN
Published: August 2005

Two-dimensional (2-D) fractal lattices, that can be representative of fracture surface/aperture roughness or 2-D permeability distribution in a porous medium, are generated using fractional Brownian motion (fBm) for different grid sizes. Invasion percolation simulations are applied on these lattices to investigate the influences of the grid size on displacement. It is found that the selection of the number of grids for computer experimentation of displacement processes is critical. The fractal dimension of the invasion cluster decreases with increasing fractal dimension of the lattice and the number of grids of the lattice. In modeling the displacement processes in fractal porous media or a single fracture between two rough surfaces, consistent fractal behavior is expected any value of the number of grids above 128 × 128. Hence, one should be careful in selecting the number of points in measuring the permeability distribution in a 2-D porous medium or roughness of the fracture surfaces.
HIDDEN VARIABLE VECTOR VALUED FRACTAL INTERPOLATION FUNCTIONS
Authors: BOUBOULIS P. , DALLA L.
Published: August 2005

We present a method of construction of vector valued bivariate fractal interpolation functions on random grids in ℝ2. Examples and applications are also included.
ASSESSMENT OF MUSICAL QUALITY OF TANPURA BY FRACTAL-DIMENSIONAL ANALYSIS
Authors: SENGUPTA R. , DEY N. , DATTA A. K. , GHOSH D.
Published: August 2005

Tanpura is a multi-stringed accompanying drone instrument extensively used in classical music in India. The instrument is plucked by finger. We know that jitter, shimmer and complexity perturbations (CP) are found also in tanpura signals. The source of origin of these perturbations was reported to be related to some sort of nonlinearity associated with the strings and their mode of attachment.

The objective of the present study is to see in what way fractal-dimensional analysis may be helpful to relate the apparent nonlinearity and also if there is any relation of these dimensions with different part of the signals like attack time, quasi-steady state and the decay.

In the paper fractal dimension, D0 and generalized dimensions, D2 to D10 and their dynamic behavior over time are studied for 15 tanpuras having four strings each, tuned to Pa (5th note), Sa (tonic), Sa (tonic) and Sa′ (lower octave tonic). The obeying of power law indicates nonlinearity in the production source system.

The presence of multifractality is studied through an examination of relationship between q and Dq and the functional relationship between Dqs.
Doubly-Binomial Option Pricing with Application to Insurance Derivatives
Authors: Chang Carolyn W. , Chang Jack S. K.
Published: August 2005

We generalize the standard lattice approach of Cox, Ross, and Rubinstein (1976) from a fixed sum to a random sum in a subordinated process framework to accommodate pricing of derivatives with random-sum characteristics. The asset price change now is determined by two independent Bernoulli trials on information arrival/non-arrival and price up/down, respectively. The subordination leads to a nonstationary trinomial tree in calendar-time, while a time change to information-time restores the simpler binomial tree that now grows with the intensity of information arrival irrespective of the passage of calendar-time. We apply the model to price the CBOT catastrophe futures call spreads as a binomial sum of binomial prices, which illuminates the information conveyed by the randomness of catastrophe arrival. Numerical results demonstrate that the standard binomial formula that ignores random claim arrival produces largest undervaluation error for out-of-money short-maturity options when a small number of significant catastrophes may strike during the option's maturity.
An Empirical Study of Optimal Bank Corrective Action for Indonesia Employing the Dynamic Contingent Claims Model
Authors: Hall Maximilian J. B. , Mustika Ganjar
Published: August 2005

This study highlights how banking regulation in Indonesia can be improved with a view to enhancing the cost-effectiveness of banking regulation and social welfare, and preventing future financial instability. We employ the Fries, Mella-Barral, and Perraudin (FMP) model (1997) and analyze the model under a robust regulatory regime concept to provide a new framework for banking regulation. Maximum likelihood estimates in VAR and GARCH are applied to monthly data on the market returns and deposit values for relatively-large banks. The results show how the authorities in Indonesia can establish optimal closure rules for each bank, levy "fair" deposit insurance premiums, estimate optimal subsidies (for different deposit insurance premiums) and identify the banks' "imminence to bankruptcy".
Convertible Bonds Issuance Terms, Management Forecasts, and Earnings Management: Evidence from Taiwan Market
Authors: Chin Chen-Lung , Lin Tyrone T. , Lee Chia-Chi
Published: August 2005

Convertible bond (CB) issuers have been required to include financial forecasts in prospectuses filed with the Taiwan Securities and Futures Commission (TSFC) since 1991. This study examines the association between CB issuance terms and the extent of optimistic initial earnings forecasts and earnings management, as well as the association between CB issuance terms and the extent of reported (post-managed) earnings forecasts. Empirical results indicate that: (1) the likelihood of the issuing company making an optimistic initial earnings forecast (positive initial forecast error) increases with conversion price, issuance amount, and issuance period, but decreases with an increasing conversion period and reselling premium; (2) earnings management was pervasive in the year of issue of the CB; and (3) a substitutive relation exists between earnings management and issuance terms in CB issuing.
ROBUSTNESS VERSUS REDUNDANCY IN BIOLOGICAL SYSTEMS
Authors: CAPOBIANCO ENRICO
Published: August 2005

Genetic networks offer a wealth of data; this is mainly due to the genomic dimensionality rather than the samples, as the latter usually come from measurements obtained under a few experimental conditions or time points. It is therefore a challenging task to design suitable statistical models and to develop effective reverse engineering algorithms. The signature of noise is pervasive in genetic networks. For instance, in perturbation experiments only a few genes change expression value, while most genes are either noisy or constant. Consequently, a genetic regulatory network is a redundant system, due to the high-dimensionality and the dependence between genes, and also a sparse system through the gene-gene interaction matrix only partially active. In order to explore these two aspects, redundancy and sparsity, independent component analysis (ICA) is proposed as a flexible approximation model targeted to dimensionality reduction and gene feature selection.
GENERAL FRAMEWORK FOR CONSISTENT SAMPLING IN HILBERT SPACES
Authors: ELDAR YONINA C. , WERTHER TOBIAS
Published: August 2005

We introduce a general framework for consistent linear reconstruction in infinite-dimensional Hilbert spaces. We study stable reconstructions in terms of Riesz bases and frames, and generalize the notion of oblique dual frames to infinte-dimensional frames. As we show, the linear reconstruction scheme coincides with the so-called oblique projection, which turns into an ordinary orthogonal projection when adapting the inner product. The inner product of interest is, in general, not unique. We characterize the inner products and the corresponding positive operators for which this geometrical interpretation applies.
SAMPLING SEQUENCES OF COMPACTLY SUPPORTED DISTRIBUTIONS IN Lp(R)
Authors: PESENSON ISAAC
Published: August 2005

The aim of the paper is to obtain some generalizations of the so-called Plancherel–Polya inequalities which are also known as frame inequalities. By using these inequalities we show that a function f ∈ Lp(R), 1 ≤ p ≤ ∞, which is entire function of exponential type is uniquely determined by a set of numbers {Φj(f)}, j ∈ ℕ where {Φj}, j ∈ ℕ is a countable sequence of compactly supported distributions. In the case p = 2 we offer two reconstruction methods of a function f from a sequence of samples {Φj(f)}, j ∈ ℕ. The first reconstruction algorithm is given in terms of frames. To describe our second algorithm we introduce the so-called average variational splines.
VARIABLE SAMPLING OF THE EMPIRICAL MODE DECOMPOSITION OF TWO-DIMENSIONAL SIGNALS
Authors: LINDERHED ANNA
Published: August 2005

Previous work on empirical mode decomposition in two dimensions typically generates a residue with many extrema points. In this paper we propose an improved method to decompose an image into a number of intrinsic mode functions and a residue image with a minimum number of extrema points. We further propose a method for the variable sampling of the two-dimensional empirical mode decomposition. Since traditional frequency concept is not applicable in this work, we introduce the concept of empiquency, shortform for empirical mode frequency, to describe the signal oscillations. The very special properties of the intrinsic mode functions are used for variable sampling in order to reduce the number of parameters to represent the image. This is done blockwise using the occurrence of extrema points of the intrinsic mode function to steer the sampling rate of the block. A method of using overlapping 7 × 7 blocks is introduced to overcome blocking artifacts and to further reduce the number of parameters required to represent the image. The results presented here shows that an image can be successfully decomposed into a number of intrinsic mode functions and a residue image with a minimum number of extrema points. The results also show that subsampling offers a way to keep the total number of samples generated by empirical mode decomposition approximately equal to the number of pixels of the original image.
Periods for holomorphic maps via Lefschetz numbers
Authors: Llibre Jaume , Todd Michael
Published: August 2005

We characterise the set of fixed points of a class of holomorphic maps on complex manifolds with a prescribed homology. Our main tool is the Lefschetz number and the action of maps on the first homology group.
Estimation of the best constant involving the L2 norm of the higher‐order Wente problem
Authors: Baraket Sami , Dammak Makkia
Published: August 2005

We study the best constant involving the L2 norm of the p‐derivative solution of Wente′s problem in ℝ2p. We prove that this best constant is achieved by the choice of some function u. We give also explicitly the expression of this constant in the special case p = 2.
Global attractor for the lattice dynamical system of a nonlinear Boussinesq equation
Authors: Abdallah Ahmed Y.
Published: August 2005

We will study the lattice dynamical system of a nonlinear Boussinesq equation. Our objective is to explore the existence of the global attractor for the solution semiflow of the introduced lattice system and to investigate its upper semicontinuity with respect to a sequence of finite‐dimensional approximate systems. As far as we are aware, our result here is the first concerning the lattice dynamical system corresponding to a differential equation of second order in time variable and fourth order in spatial variable with nonlinearity involving the gradients.
On the existence of nontrivial solutions for a fourth‐order semilinear elliptic problem
Authors: Qian Aixia , Li Shujie
Published: August 2005

By means of Minimax theory, we study the existence of one nontrivial solution and multiple nontrivial solutions for a fourth‐order semilinear elliptic problem with Navier boundary conditions.
Characteristics of Patients with Chronic Cough Who Developed Classic Asthma during the Course of Cough Variant Asthma: A Longitudinal Study
Authors: Nakajima Takeo , Nishimura Yoshihiro , Nishiuma Teruaki , Kotani Yoshikazu , Funada Yasuhiro , Nakata Hiroyuki , Yokoyama Mitsuhiro
Published: August 2005

Background: Some patients develop asthmatic symptoms such as wheezing and dyspnea during the course of cough variant asthma (CVA), which are considered precursors of classical asthma. Objectives: To identify the characteristics of such patients, we investigated the nature of CVA patients with or without developing bronchial asthma in the longitudinal study. Methods: In 28 CVA patients whom we could observe over 5 years, duration of coughing, physical examination findings, pulmonary function and bronchial hyperresponsiveness to inhaled methacholine were retrospectively assessed. Results: Of these patients with CVA, 10 developed the asthmatic symptoms of wheezing and dyspnea (precursors of classical asthma) over 5 years. All these 10 patients showed marked bronchial hyperresponsiveness; however, there were no significant differences in the bronchial responsiveness to methacholine between patients with precursors of classical asthma and pure CVA patients who did not wheeze. The duration of coughing had a significant relationship with precursors of classical asthma. Seven patients with precursors of classical asthma developed wheezing in the first year and 1 patient each in the second, third and fourth year. Conclusions: These findings of a 5-year observation suggest that longer duration of coughing may be an important factor that develops precursors of classical asthma in patients with CVA.
Hemopericardium-Related Fatalities: A 10-Year Medicolegal Autopsy Experience
Authors: Altun Gurcan , Altun Armagan , Yilmaz Ahmet
Published: August 2005

Background: Patients with blunt or penetrating cardiac injury usually present with cardiac tamponade and hemorrhagic shock upon hospital arrival. Many victims die before they reach hospital. In this study, we present a detailed analysis of hemopericardium-related fatalities. Methods: We retrospectively reviewed the medicolegal autopsy records of hemopericardium-related fatalities that occurred from 1994 to 2003. The parameters investigated were demographic characteristics, hospitalization before death, the cause of death, the manner of death, the mechanism of death, the location of the entrance wound, the number of wounds reaching the target and the site of target perforation. Results: Seven women (mean age: 45 ± 23 years) and 33 men (mean age: 34 ± 12 years) were included in the study. Only 5 patients (12.5%) with cardiac activity reached the hospital. Twenty individuals (50%) were victims of stabbings, which was the most common cause of death. The most commonly encountered manner of death was homicide (79%). Thirty-one (77.5%) victims died of hemorrhagic shock and 9 (22.5%) of cardiac tamponade. Entrance wounds were frequently located on the left chest (n = 26). The perforated cardiac chambers were the left atrium (n = 1), the left ventricle (n = 12), the right atrium (n = 2) and the right ventricle (n = 15). One victim had coronary artery perforation. Nine victims had perforations on the intrapericardial part of the aorta. Conclusions: In our series, the hemopericardium-related deaths occurred predominantly in men. Stabbing was the most common cause of death. Entrance wounds were most commonly located on the left chest, and perforated sites were ventricles. Death at the scene was also frequent, and the mechanism of death was hemorrhagic shock.
Hormone Replacement Therapy and Secondary Cardiovascular Prevention: A Meta-Analysis of Randomized Trials
Authors: Cho Leslie , Mukherjee Debabrata
Published: August 2005

Background: Coronary artery disease is the leading cause of death in women. Several randomized clinical trials of hormone replacement therapy (HRT) in women with and without coronary artery disease have found no benefit of HRT in decreasing cardiovascular events. The purpose of this study was to assess the benefits and risks of HRT for prevention of cardiovascular events by conducting a meta-analysis of all randomized trials of HRT, and estimate cardiovascular event rates. Methods and Results: All relevant randomized, clinical trials were identified in MEDLINE (1966–2001), HealthSTAR (1975–2001), and Cochrane Library databases. The search terms were hormone replacement or HRT[, ]estrogen[, ]progesterone[, ]women and heart disease. We used all published data of randomized, clinical trials of HRT if they reported cardiovascular endpoints. Meta-analysis of the randomized, clinical trials involving 21,066 patients revealed that HRT did not reduce mortality compared with control group (1.9 vs. 1.9%, odds ratio 1.05, 95% CI 0.86–1.30, p = 0.58) or significantly reduce risk of myocardial infarction (3.7 vs. 3.7%, odds ratio 1.04, 95% CI 0.90–1.21, p = 0.58) or revascularization (6.4 vs. 6.8%, odds ratio 0.95, 95% CI 0.85–1.08, p = 0.50). The rate of acute coronary syndrome rate was 9.1% in the HRT group vs. 9.3% with odds ratio 1.00, 95% CI 0.90–1.12, p = 0.98. Conclusion: HRT use is not associated with reduced death, myocardial infarction or revascularization rate. This suggests that HRT is not an effective secondary cardiovascular preventive measure.
Hyperplastic Cellular Remodeling of the Media in Ascending Thoracic Aortic Aneurysms
Authors: Tang Paul C.Y. , Coady Michael A. , Lovoulos Constantinos , Dardik Alan , Aslan Mihaela , Elefteriades John A. , Tellides George
Published: August 2005

Background—

Progressive medial degeneration and atrophy is thought to be a cause of ascending thoracic aortic aneurysms in the elderly. Extensive apoptosis of vascular smooth muscle cells (VSMCs) has been demonstrated in the media of abdominal aortic aneurysms. We investigated whether medial atrophy from loss of VSMCs occurs in primary ascending thoracic aortic aneurysms.

Methods and Results—

Morphometric analysis of 28 nonaneurysmal ascending thoracic aortas and 29 ascending thoracic aortic aneurysms was performed by directly measuring the thickness of their vascular layers and by indirectly calculating the area of their vascular compartments. The cellular and matrix composition of the media was assessed at the structural, protein, and transcript levels. Despite thinning of the media secondary to vascular dilatation, there was an overall increase in the medial area of aneurysms. VSMC density was preserved, implying cellular hyperplasia as a result of the increased medial mass. There was decreased expression of matrix proteins, despite sustained synthesis of these molecules, which was associated with evidence of increased matrix degradation. The remodeling and expansion of the media was most evident in comparisons between nonaneurysmal aortas versus smaller aneurysms and did not evolve further in larger aneurysms.

Conclusions—

The mechanisms for luminal enlargement in thoracic and abdominal aortic aneurysms differ significantly with regard to the survival of VSMCs and atrophy of the media but share common pathophysiology involving degeneration of the matrix. Hyperplastic cellular remodeling of the media in ascending thoracic aortic aneurysms may be an initial adaptive response to minimize increased wall stress resulting from vascular dilatation.