bluuebunny/crossref_metadata_2025 huggingface dataset:
VARIATION OF ATTENUATED TOTAL REFLECTION AND SECOND HARMONIC GENERATION OF MIXED NEMATIC LIQUID CRYSTALS
Authors: DONG R. L. , LIN T. S. , LUE J. T.
Published: May 2003

Optical second harmonic generation from nematic and cholesteric liquid crystals attributing to quadrupole, flexoelectric effect and electric field induced nonlinear susceptibility is detected. The measured second harmonic generation (SHG) intensity is proportional to the square of the applied field irrespective of whether the field is alternate or direct current. The SHG intensity can be enhanced by the surface plasmons generated by attenuated total reflection (ATR) installed by the Kretcshmann–Raether configurations. The small angle shift of the ATR minimum under various change of bias as large as 40 V can be satisfactorily expressed by the three layered system in which the indices of two outer layers retained in their original values by the strong anchoring effect.
NONLINEAR OPTICAL RESPONSES OF ANTIFERROMAGNETIC INSULATORS
Authors: HANAMURA EIICHI , TANABE YUKITO
Published: May 2003

Firstly, we show how to resolve the observed mystery in the resonance-enhancement of two-magnon Raman scattering in antiferromagnetic (AFM) insulators La2CuO4 and YBa2Cu3O6 in terms of the excitonic cluster model. Secondly, we refer to the strong third-harmonic generation (THG) in visible region from La2CuO4, and explain how we are able to understand the fine structures as quantum interference among two-photon and three-photon resonant THG.

Ferroelectric (FEL)-AFM crystals RMnO3 (R=Y, Ho, Er) with a hexagonal structure show interesting two-photon resonant second-harmonic generation (SHG). Two lowest-energy excitons in the visible region are found to contribute to SHG constructively in YMnO3 and destructively in ErMnO3 depending upon the AFM spin-configuration. It is also found that the clamping of two order-parameters FEL and AFM must be introduced to explain the observation.
PLASMON MODES IN METAL NANOWIRES AND LEFT-HANDED MATERIALS
Authors: PODOLSKIY VIKTOR A. , SARYCHEV ANDREY K. , SHALAEV VLADIMIR M.
Published: May 2003

The electromagnetic field distribution for thin metal nanowires is found, by using the discrete dipole approximation. The plasmon polariton modes in wires are numerically simulated. These modes are found to be dependent on the incident light wavelength and direction of propagation. The existence of localized plasmon modes and strong local field enhancement in percolation nanowire composites is demonstrated. Novel left-handed materials in the near-infrared and visible are proposed based on nanowire composites.
TERAHERTZ TIME-DOMAIN SPECTROSCOPY BASED ON NONLINEAR OPTICS
Authors: SHAN JIE , NAHATA AJAY , HEINZ TONY F.
Published: May 2003

We present a brief review of the use of nonlinear optics for broadband terahertz (THz) time-domain spectroscopy with femtosecond laser pulses. The generation of THz pulses is accomplished by optical rectification and coherent detection by electro-optic sampling or field-induced second-harmonic generation. The approach permits exceptional time response, as well as the possibility for multichannel detection schemes.
COHERENT AND TUNABLE TERAHERTZ OSCILLATORS, GENERATORS, AND AMPLIFIERS
Authors: DING YUJIE J. , ZOTOVA IOULIA B.
Published: May 2003

We have considered feasibilities of using optical parametric oscillation and amplification, and difference-frequency generation for efficiently generating and amplifying terahertz waves in several second-order nonlinear optical materials. They include GaAs, GaP, GaSe, CdSe, LiNbO3 and LiTaO3. The advantage of using birefringence in CdSe and GaSe is tunability of the output terahertz frequency. Furthermore, both CdSe and GaSe can be used to achieve the backward parametric oscillation without any cavity. On the other hand, in periodically-poled LiNbO3 and LiTaO3, one can take advantage of large diagonal elements of second-order nonlinear susceptibility tensor. In the diffusion-bonded-stacked GaAs and GaP plates, quasi-phase matching can be achieved by alternatively rotating the plates. It is also feasible to achieve phase matching in a single GaAs or GaP plate due to the presence of the absorption tail of polariton modes. In this case, tuning can be achieved by changing the pump wavelength. The advantages of using coherent parametric processes are possibilities of efficiently generating and amplifying temporally-coherent and narrow-linewidth tunable terahertz waves at room temperature. However, all other schemes do not possess these advantages. Compared with a noncollinear configuration, by using the parallel wave propagation configurations, the conversion efficiency can be higher because of longer effective interaction length among all the waves.
LASER-INDUCED RIPPLE STRUCTURE OF DOPANT ON THE SUBSTRATES IN A DYE–DOPED LIQUID CRYSTAL CELL AND ITS ALIGNMENT EFFECT
Authors: FUH ANDY Y.-G. , LIAO C.-C. , HSU K.-C. , LU C.-L. , MO T.-S.
Published: May 2003

This paper describes a recording of a holographic grating on a homeotropically aligned dye-doped liquid crystal (DDLC) cell. The photo-excited azo dyes, methyl red (MR), diffuse and adsorb onto the substrates, thereby forming a ripple structure. The adsorbed dye and the laser-induced ripple structure then reorientate the liquid crystal molecules, and induce a holographic grating.
NOVEL CRYSTALLIZATION METHOD: RING-HEATER HEATED PEDESTAL GROWTH METHOD FOR NONLINEAR OPTICAL ORGANIC MATERIAL
Authors: TAIMA T. , KOMATSU K. , KAINO T.
Published: May 2003

We developed a novel crystal growth method from molten state, ring-heater heated pedestal growth method (RHHPG), where we can easily control a crystal growth direction of organic nonlinear optical (NLO) crystal. We focused on 2-adamantylamino-5-nitropyridine (AANP) as an NLO crystal for this research work. We controlled its crystal growth direction toward a phase-matched direction at telecommunication wavelength by using the RHHPG method.
DISTINCT DYNAMIC REGIMES IN A MATERIAL SYSTEM WITH OPTICALLY MODULATED DIFFUSIVITY
Authors: CAPUTO R. , SUKHOV A. V. , TABIRYAN N. V. , UMETON C.
Published: May 2003

We report on distinct dynamic regimes of optically induced redistribution of molecules in a reacting material. The physical system is a mixture of photopolymerizable monomer and nematic liquid crystal with space-time modulated diffusivity. An empirical model is developed which provides an excellent description of all the stages of the experimentally observed highly intricate dynamics. This dynamics is governed by spatially inhomogeneous photogeneration of radicals, their diffusion, and the photopolymerization-induced change in the diffusion constant.
LIGHT-INDUCED ADSORPTION AND DESORPTION IN DYNAMIC AND STABLE GRATING FORMATION IN METHYL-RED DOPED LIQUID CRYSTALS
Authors: LUCCHETTI L. , DI FABRIZIO M. , FRANCESCANGELI O. , SIMONI F.
Published: May 2003

A detailed study of the light-induced gratings in Methyl-Red-doped 4-n-pentyl-4′-cyanobiphenyl (5CB) homeotropically aligned is reported. In particular, the dependence of diffraction efficiency upon the pump and probe polarizations has been investigated both for transient and permanent gratings. Our results confirm the earlier observations on the role of light-induced adsorption of MR molecules on the cell boundaries and demonstrate the common origin of the supranonlinear response and the permanent recording effect.
HIGH ACCURACY OPTICAL BISTABLE INTERFEROMETRIC FIBER SENSORS
Authors: LI CHUNFEI , ZHOU FEI , YANG KUN
Published: May 2003

A novel optical fiber sensing technique for length and temperature measurement with accuracy of sub-nanometer and 10-4° C , respectively, is proposed. The new kind of sensor is a combination of a conventional interferometric sensor and a hybrid optical bistable device. The measurement is accomplished by counting the number of electrical pulses, provided by switching on and switching off of the optical bistability periodically. An optical bistable fiber sensor with a March–Zehnder interferometer is analyzed in this paper. The main advantages of this technique lie in the adjustable high accuracy and ability to distinguish the variation direction of quantities to be measured.
FABRICATION AND CHARACTERIZATION OF MULTILAYER WAVEGUIDE FOR INTEGRATED OPTICS
Authors: SHARMA SUDHIR KUMAR , SHARMA V. K. , TRIPATHI K. N.
Published: May 2003

We report on our systematic and detailed study of fabrication and characterization of polyaniline (PA) prepared by vacuum deposition and polystyrene (PS) prepared by dip coating method thin film optical waveguides. The four-layer consisting of substrate (glass)/PA/PS/air has been used for demonstrating polarization filter action.
AN EXPLICIT CALCULATION OF THE DISPERSIVE AND NONLINEAR FREQUENCY CHIRPS FOR FEMTOSECOND OPTICAL PULSES OF THE HIGH DISPERSIVE CUBIC AND CUBIC–QUINTIC NONLINEAR SCHRÖDINGER EQUATIONS
Authors: PALACIOS S. L.
Published: May 2003

The cancellation of the dispersive and nonlinear phase components on the optical pulses of a nonlinear Schrödinger equation in the presence of fourth order dispersion and a parabolic refractive index profile is explicitly demonstrated when hyperbolic function pulses are injected. With the help of the split step Fourier method we obtain the frequency chirp associated with GVD and SPM phenomena. Its mutual compensation leads to the analytical exact soliton solutions of the high dispersive cubic and cubic quintic nonlinear Schrödinger equations.
NONLINEAR DYNAMIC OSCILLATIONS OF OPTICAL TRANSMITTANCE FOR NEMATIC LIQUID CRYSTALS AFTER THE TURN-OFF OF APPLIED ELECTRIC FIELDS
Authors: HUANG PENG-RU , LIN TZONG-SHYAN , LUE JUH-TZENG
Published: May 2003

Relaxation oscillations of optical transmittance after the turn-off of the applied electric field of liquid crystals are observed when the detected light transmits through a proper adjustment of the alignment of the polarizer and analyzer. Monte Carlo simulation of the equilibrium tilting and twisting angles of molecules at each layer that yield relevant polarization of the transmitted light can satisfactorily portrait this phenomenon. Optics of an isotropic-layered liquid crystal with the extended Jones 4 × 4 matrix formalism is implemented to solve this problem. The transmittance under linear changes of temperatures also reveals similar nonlinear relaxation oscillations.
PHOTOREFRACTIVE EFFECT OF Ce:Fe:LiNbO3 CRYSTAL
Authors: WANG RUI , WEI YONGDE , WANG BIAO
Published: May 2003

Ce:Fe:LiNbO 3 crystals were grown by Czochralski method, and was treated by oxidation or reduction. It was found that the exponential gain coefficient for the crystal with thickness of 0.5 mm was two times higher than that for one with the thickness of 2 mm. The effective charge density of the crystals with the reduction treatment was two times higher than that of the one with the oxidation treatment. The maximum phase conjugate reflectivity of crystals with the thickness of 2 mm was 75%.
DARK SOLITONS IN OPTICAL FIBERS WITH HIGHER ORDER EFFECTS
Authors: NAKKEERAN K.
Published: May 2003

We consider the higher order nonlinear Schrödinger (HNLS) equation, which governs the nonlinear wave propagation in optical fibers with higher order effects. Lax pair associated with the integrable HNLS equation for the pulse propagation in normal dispersion regime of the fiber media is constructed with the help of Ablowitz–Kaup–Newell–Segur method. Using Hirota bilinear method, dark soliton solution is explicitly derived. Similar study is also carried out for simultaneous propagation of N nonlinear pulses in the normal dispersion regime of the fiber system with higher order effects.
SOLITON PULSE COMPRESSION IN A DISPERSION DECREASING ELLIPTIC BIREFRINGENT FIBER WITH EFFECTIVE GAIN AND EFFECTIVE PHASE MODULATION
Authors: GANAPATHY R. , KURIAKOSE V. C.
Published: May 2003

We have considered soliton pulse compression in a dispersion decreasing ideal elliptical birefringent fiber with phase modulation. We have shown that there is exact balancing between the effective gain and the effective phase modulation and as a result arrive at the fundamental soliton solution. For the various dispersion decreasing profiles we have considered, we have shown that the hyperbolic profile is the best suitable choice for the dispersion decreasing profile as it provides fairly good compression even after compensating for the fiber loss.
WEAK AND STRONG MARTINGALE CONVERGENCES OF GENERALIZED CONDITIONAL EXPECTATIONS IN NONCOMMUTATIVE Lp-SPACES
Authors: FIDALEO FRANCESCO
Published: May 2003

While briefly reviewing results about (nets of) generalized conditional expectations and martingale-type convergences, we present an unified version of the topic and prove martingale-type convergence results of monotone nets of generalized conditional expectations in the full generality. In so doing, we fill some gaps.
QUANTUM ENTROPY AND INFORMATION IN DISCRETE ENTANGLED STATES
Authors: BELAVKIN VIACHESLAV P. , OHYA MASANORI
Published: May 2003

Quantum entanglements, describing truly quantum couplings, are studied and classified for discrete compound states. We show that classical-quantum correspondences such as quantum encodings can be treated as d-entanglements leading to a special class of separable compound states. The mutual information for the d-compound and for q-compound (entangled) states leads to two different types of entropies for a given quantum state. The first one is the von Neumann entropy, which is achieved as the supremum of the information over all d-entanglements, and the second one is the dimensional entropy, which is achieved at the standard entanglement, the true quantum entanglement, coinciding with a d-entanglement only in the commutative case. The q-conditional entropy and q-capacity of a quantum noiseless channel, defined as the supremum over all entanglements, is given as the logarithm of the dimensionality of the input von Neumann algebra. It can double the classical capacity, achieved as the supremum over all semiquantum couplings (d-entanglements, or encodings), which is bounded by the logarithm of the dimensionality of a maximal Abelian subalgebra. The entropic measure for essential entanglement is introduced.
QUANTUM DECOMPOSITION IN DISCRETE GROUPS AND INTERACTING FOCK SPACES
Authors: HASHIMOTO YUKIHIRO
Published: May 2003

We introduce a kind of quantum decomposition of generators of a discrete group with a suitable length function and construct a sequence of one-mode interacting Fock spaces associated with a filtration of the group. We show stochastic convergence of such a sequence of interacting Fock spaces and obtain a general stochastic limit theorems on discrete groups. As an application to free groups, we see that the Haagerup states give rise to a Gaussian–Poisson transform through its coherent expression.
ON THE UNIQUENESS OF THE CHENTSOV METRIC IN QUANTUM INFORMATION GEOMETRY
Authors: GRASSELLI M. R. , STREATER R. F.
Published: May 2003

We show that, in finite dimensions, the only monotone metrics on the space of invertible density matrices for which the (+1) and (-1) affine connections are mutually dual are constant multiples of the Bogoliubov–Kubo–Mori metric.
RENORMALIZED TRACES AS A LOOKING GLASS INTO INFINITE-DIMENSIONAL GEOMETRY
Authors: PAYCHA SYLVIE
Published: May 2003

This paper, based on results obtained in recent years with various coauthors,1–3,13,53 presents a proposal to extend some classical geometric concepts to a class of infinite-dimensional manifolds such as current groups and to a class of infinite-dimensional bundles including the ones arising in the family index theorem.

The basic idea is to extend the notion of trace underlying many geometric concepts using renormalized traces which are linear functionals on pseudo-differential operators. The definition of "renormalized traces" involves extra data on the manifolds or vector bundles, namely a weight given by a field of elliptic operators which becomes part of the geometric data, leading to the notion of weighted manifold and weighted vector bundle. This weight is a source of anomaly arising typically as a Wodzicki residue of some pseudo-differential operator.

We investigate the anomalies that arise when trying to extend to the infinite-dimensional setting classical results of finite-dimensional geometry such as a Weitzenböck formula, Chern–Weil invariants or the relation between the first Chern form on a complex vector bundle and the curvature on the associated determinant bundle. When comparable, we relate our approach to the one adopted for similar problems in noncommutative geometry.
ANALYTIC CHARACTERIZATION OF ONE-MODE INTERACTING FOCK SPACE
Authors: ASAI NOBUHIRO
Published: May 2003

In this paper, we shall give the Segal–Bargmann representation space of the one-mode interacting Fock space. For this purpose, we shall define the generalized coherent vector associated with the Szegö–Jacobi parameters and introduce the associated integral transformation.
COMPLEX WHITE NOISE ANALYSIS
Authors: REDFERN MYLAN
Published: May 2003

This paper describes a new space, [Formula: see text], of complex Wiener distributions for the analysis of multi-parameter generalized stochastic processes [Formula: see text]. For a certain class of functions [Formula: see text] and complex Wiener integrals Φ1, …, Φm, F(Φ1, …, Φm) is defined as an element of [Formula: see text] and its Fock space decomposition determined.
FILTERED STOCHASTIC CALCULUS
Authors: LENCZEWSKI ROMUALD
Published: May 2003

By introducing a color filtration to the multiplicity space [Formula: see text], we extend the quantum Itô calculus on multiple symmetric Fock space [Formula: see text] to the framework of filtered adapted biprocesses. In this new notion of adaptedness, "classical" time filtration makes the integrands similar to adapted processes, whereas "quantum" color filtration produces their deviations from adaptedness. An important feature of this calculus, which we call filtered stochastic calculus, is that it provides an explicit interpolation between the main types of calculi, regardless of the type of independence, including freeness, Boolean independence (more generally, m-freeness) as well as tensor independence. Moreover, it shows how boson calculus is "deformed" by other noncommutative notions of independence. The corresponding filtered Itô formula is derived. Existence and uniqueness of solutions of a class of stochastic differential equations are established and unitarity conditions are derived.
MONOTONE INDEPENDENCE IS ASSOCIATIVE
Authors: FRANZ UWE
Published: May 2003

It is shown that the notion of monotone independence introduced by Muraki and Lu leads to an associative product of quantum probability spaces. This product is then used to define monotone Lévy processes on dual semigroups.
FINITE DIMENSIONAL APPROXIMATIONS OF DIFFUSION PROCESSES ON BANACH SPACES
Authors: ZHANG T. S.
Published: May 2003

In this paper, we prove that the laws of diffusion processes on a Banach space X associated with quadratic forms (not necessarily symmetric) are the weak limits of laws of finite dimensional diffusions. A new existence proof for the infinite dimensional diffusion processes is obtained as a by-product.
MULTIPLE INTERSECTION LOCAL TIMES IN TERMS OF WHITE NOISE
Authors: MENDONÇA SANDRA , STREIT LUDWIG
Published: May 2003

We show how multiple intersections of Brownian motion can be expressed in terms of generalized white noise functionals. We also calculate the kernels of their chaos expansions and discuss their L2 properties.
GENERALIZED ANALYTIC FUNCTIONS ON THE COUNTABLE PRODUCT AND DIRECT SUM OF THE COMPLEX NUMBERS
Authors: PETERSSON HENRIK
Published: May 2003

A classical result states that, in n variables, the space of the entire functionals can be identified with the space of exponential type functions via the Fourier–Borel transform. Thus, in this way the spaces of the entire and exponential type functions can be put in duality, the Martineau duality. We give a proof that the entire functionals, on the countable direct product and direct sum of the field of complex numbers, can be identified with exponential type functions in the same way. In other words, we show that the infinite dimensional Fourier–Borel transform defines Martineau dualities analogous to the finite dimensional case.
STUDY OF GAMOW STATES IN THE RIGGED HILBERT SPACE WITH TEMPERED ULTRADISTRIBUTIONS
Authors: DE PAOLI A. L. , ESTEVEZ M. A. , ROCCA M. C. , VUCETICH H.
Published: May 2003

In this work we show that it is possible to extend analytically, and with the use of tempered ultradistributions, the "pseudonorm" defined by T. Berggren for Gamow states. We define this "pseudonorm" for all states determined by the zeros of the Jost function for any short range potential.

As an example we study the s-states corresponding to the square well potential.
ON THE UNITARITY OF STOCHASTIC EVOLUTIONS DRIVEN BY THE SQUARE OF WHITE NOISE
Authors: ACCARDI LUIGI , BOUKAS ANDREAS , KUO HUI-HSUNG
Published: May 2003

Using the closed Itô's table for the renormalized square of white noise, recently obtained by Accardi, Hida, and Kuo in Ref. 4, we consider the problem of providing necessary and sufficient conditions for the unitarity of the solutions of a certain type of quantum stochastic differential equations.
ON ERGODIC BEHAVIOR OF p-ADIC DYNAMICAL SYSTEMS
Authors: GUNDLACH MATTHIAS , KHRENNIKOV ANDREI , LINDAHL KARL-OLOF
Published: May 2003

Monomial mappings, x ↦ xn, are topologically transitive and ergodic with respect to Haar measure on the unit circle in the complex plane. In this paper we obtain an analogous result for monomial dynamical systems over p-adic numbers. The process is, however, not straightforward. The result will depend on the natural number n. Moreover, in the p-adic case we will not have ergodicity on the unit circle, but on the circles around the point 1.
GAUSS FORMULA AND SYMMETRIC EXTENSIONS OF THE LAPLACIAN ON CONFIGURATION SPACES
Authors: FINKELSHTEIN D. L. , KONDRATIEV YU. G. , RÖCKNER M. , KONSTANTINOV A. YU.
Published: May 2003

We prove an analogue of the classical Gauss formula for the configuration space ΓΛ over a domain Λ of ℝd and study symmetric extensions of the corresponding Laplacian on ΓΛ.
DIVERGENCE RESULTS FOR SELF-INTERSECTION LOCAL TIMES OF GAUSSIAN ${\mathscr S}' ({\mathbb R}^d)$-PROCESSES
Authors: TALARCZYK ANNA
Published: May 2003

For various types of Gaussian [Formula: see text]-processes we consider the case when the self-intersection local time (SILT) does not exist. We study the rate of divergence of the corresponding approximating processes obtaining, after suitable normalizations convergence in law to some [Formula: see text]-valued processes (not necessarily Gaussian). We also obtain some new necessary conditions for the existence of SILT. We give examples associated with fluctuation limits of α-stable particle systems.
TIGHT BOUNDS FOR BROADCASTING IN THE LINEAR COST MODEL
Authors: BEAUQUIER BRUNO , PÉRENNES STÉPHANE , DELMAS OLIVIER
Published: May 2003

This work considers broadcast protocols made of successive communication rounds in the linear cost model: the time needed to send a message of length L is defined as α + Lτ, where α stands for a start-up time while Lτ represents the cost of sending L bits of data in a channel with bandwidth 1/τ. In this model, the communication time of any algorithm [Formula: see text] is expressed as the sum [Formula: see text], where [Formula: see text] is the number of rounds and [Formula: see text] the transmission cost of the algorithm. In order to design an efficient algorithm realizing a given communication pattern, it appears that minimizing [Formula: see text] and [Formula: see text] are antinomic goals. We study this trade-off issue for broadcast protocols. Surprisingly, such a general theoretical study has almost never been done. In the literature, only the two opposite issues are actually considered: minimizing the number of rounds in the case of short messages, or minimizing the transmission cost in the case of large messages. Our results concern the fully-connected N-nodes network KN, with N = (k + 1)T, in the bidirectional k–ports mode. We derive tight bounds on the communication time for broadcasting in T + r rounds, our lower bounds holding for any network.
OPTIMAL CARRIER SHARING IN WIRELESS TDMA
Authors: BORST S. C. , COFFMAN E. G. , GILBERT E. N. , WHITING P. A. , WINKLER P. M.
Published: May 2003

To improve efficiency, we allow a carrier in a TDMA (Time Division Multiple Access) network to be shared by adjacent cells. This sharing of time slots is seriously hampered by the lack of synchronization in distinct cells. We study packing algorithms that overcome this obstacle by clustering calls. The results suggest that even simple greedy algorithms are nearly optimal, and that little extra performance can be gained either by allowing the rejection of calls or by repacking.
EXPOSED LAYOUTS OF THE BUTTERFLY NETWORK
Authors: LITMAN AMI
Published: May 2003

This work studies layouts of the Butterfly network under the restriction that its input and output verticles are exposed, that is, are placed on the boundary of the grid. Avior et al. have shown that the minimal area of a layout of the n-input Butterfly, without the above restriction, is (1 + o(1))n2). The effect of this restriction on the area was left as an open question. This paper reveals that exposing the input and output vertices is essentially free. That is, it presents an exposed layout of the Butterfly having the same area as above. In this layout, the fractions of the input and output vertices assigned to each side of the grid are as follows when scanning the sides in a circular fashion: half of the inputs, half of the outputs, half of the inputs, and half of the outputs. We refer to such a layout as a [Formula: see text]-layout. The main technique employed in this layout is the reduction of the layout problem of the Butterfly to a certain layout problem of a complete bipartite graph. We use the same technique to produce a (I, 0, O, 0)-layout (inputs on one side and outputs on the opposite side) in area 2 + o(1))n2. Finally, we show that the area of a [Formula: see text]-layout is greater than [Formula: see text]. Hence, this input-output configuration is more area-demanding than [Formula: see text].
CONCURRENCY CONTROL FOR MOBILE SYSTEMS WITH DATA BROADCAST
Authors: AU MEI-WAI , CHAN EDWARD , LAM KAM-YIU
Published: May 2003

Although data broadcast has been shown to be an efficient method for disseminating data items in a mobile computing system with large number of clients, the issue on how to ensure the data consistency observed by mobile transactions, which are generated by mobile clients, has been largely ignored by researchers in the area. While data items are being broadcast, update transactions may install new values for the data items. If the executions of update and broadcast of data items are interleaved without any control, the mobile transactions may observe inconsistent data values. In this paper, we propose a serialization checking method (SCM) for concurrency control between read-only mobile transactions and update transactions. SCM is based on the framework of an earlier algorithm, Update First with Ordering (UFO), but improves on that algorithm by reducing re-broadcast overhead when the probability of data conflict between updates and data broadcast is high. Simulation experiments have been performed to investigate the performance characteristics of the proposed method.
ROUTING IN HYPERCUBE NETWORKS WITH A CONSTANT FRACTION OF FAULTY NODES
Authors: CHEN JIANER , WANG GUOJUN , CHEN SONGQIAO
Published: May 2003

We consider routing in hypercube networks with a very large number (i.e., up to a constant fraction) of faulty nodes. Simple and natural conditions are identified under which hypercube networks with a very large number of faulty nodes still remain connected. The conditions can be detected and maintained in a distributed manner based on localized management. Efficient routing algorithms on hypercube networks satisfying these conditions are developed. For a hypercube network that satisfies the conditions and may contain up of 37.5% faulty nodes, our algorithms run in linear time and for any two given non-faulty nodes find a routing path of length bounded by four times the Hamming distance between the two nodes. Moreover, our algorithms are distributed and local-information-based in the sense that each node in the network knows only its neighbors' status and no global information of the network is required by the algorithms.
A PARALLEL DECOUPLING TECHNIQUE TO ACCELERATE CONVERGENCE OF RELAXATION SOLUTION OF INTEGRAL-DIFFERENTIAL-ALGEBRAIC EQUATIONS
Authors: HUANG ZU-LAN , CHEN RICHARD M. M. , JIANG YAO-LIN
Published: May 2003

In this paper, we first study the covergence performance of relaxatio-based algorithms for linear integral differential-algebraic equations (IDAEs), then a parallel decoupling technique to speed up the convergence of the relaxation-based algorithms is derived. This novel technique is suitable for implementation of parallel processing for complicated systems of IDAEs. Factors taking effect on the performance of parallel processing are discussed in detail. Large numerical examples running on a network of IBM RS/6000 SP2 system are given to illustrate how judicious partitionings of matrices can help improve convergence in parallel processing.
SIMULATION OF LONG-RANGE DEPENDENT TRAFFIC AND A SIMULATOR OF TCP ARRIVAL TRAFFIC
Authors: LI MING , JIA WEIJIA , ZHAO WEI
Published: May 2003

The long-range dependence of Internet traffic has been experimentally observed. One issue in handling long-range dependent traffic is how to simulate random traffic data with long-range dependence. The authors discuss a correlation-based simulator with a white noise input for generating long-range dependent traffic data. With the real TCP traffic traces, a simulation model of TCP arrival traffic is empirically developed and the experimental results are satisfactory.
THREE DIMENSIONAL GRID STRUCTURE FOR EFFICIENT ACCESS OF REPLICATED DATA
Authors: MAT DERIS MUSTAFA , MAMAT ALI , SENG PUA CHAI , SAMAN MOHD YAZID
Published: May 2003

This article addresses the performance of data replication protocol in terms of data availability and communication costs. Specifically, we present a new protocol called Three Dimensional Grid Structure (TDGS) protocol, to manage data replication in distributed system. The protocol provides high availability for read and write operations with limited fault-tolerance at low communication cost. With TDGS protocol, a read operation is limited to two data copies, while a write operation is required with minimal number of copies. In comparison to other protocols. TDGS requires lower communication cost for an operation, while providing higher data availability.
LOCAL-SAFETY-INFORMATION-BASED BROADCASTING IN HYPERCUBE MULTICOMPUTERS WITH NODE AND LINK FAULTS
Authors: XIANG DONG , CHEN AI , WU JIE
Published: May 2003

This paper presents a method to cope with fault-tolerant broadcasting in hypercube multicomputers with both node and link faults. The local safety concept is extended to faulty hypercubes with both node and link faults. The local-safety-based algorithm is used in a fully unsafe hypercube, where there is no safe node. A fully unsafe hypercube can be split into a set of maximal safe subcubes. We show that if these maximal safe subcubes meet certain requirements given in the paper, broadcasting can still be carried out successfully and in some case optimal broadcast is still possible. The method is extended to fault-tolerant routing and multicasting when the system contains both node and link faults.
THE DEVELOPMENT OF A MOBILE DECISION SUPPORT SYSTEM
Authors: WU YEU , TIAN YONGHONG , ZHOU WANLEI
Published: May 2003

The emergence of mobile computing environments brings out various changes in the requirements and applications involving distributed data and has made the traditional Intelligent Decision Support System (IDSS) architectures based on the client/server model ineffective in mobile computing environments. This paper discusses the deficiencies of the current IDSS architectures based on data warehouse, on-line analysis processing (OLAP), model base (MB) and knowledge based (KB) technologies. By adopting the agent technology, the paper extends the IDSS system architecture to the Mobile Decision Support System (MDSS) architecture. The logical structure and the application architecture of the MDSS and the mechanisms and implementation strategies of the User Access Agent System, a major component of the MDSS, are described in this paper.
GEOMETRICALLY NONLINEAR STABILITY ANALYSIS OF SHELLS USING GENERALIZED CONFORMING SHALLOW SHELL ELEMENT
Authors: SUN JIANHENG , LONG ZHIFEI , LONG YUQIU , ZHANG CHUNSHENG
Published: May 2003

A generalized conforming finite element theory was presented to satisfy the C1 continuity condition for plate and shell element. The effectiveness of the theory in the linear analysis has been proved. This paper discusses the membrane locking phenomenon of shallow shell element based on the satisfaction of the requirement of rigid body motion, and a technique is developed to eliminate the membrane locking phenomenon. Accordingly a geometrically nonlinear generalized conforming rectangular shallow shell element with tangential degrees of freedom of midpoints of sides is formulated. Nonlinear numerical analysis of shell stability shows that the element exhibits high precision and fast convergence characteristics.
EXACT SOLUTION OF FREE IN-PLANE VIBRATION OF SHALLOW CIRCULAR ARCHES
Authors: TÜFEKÇİ EKREM
Published: May 2003

The free in-plane vibration of a shallow circular arch with uniform cross-section is investigated by taking into account axial extension, shear deformation and rotatory inertia effects. The exact solution of the governing differential equations is obtained by the initial value method. By employing the same solution procedure, the solutions are also given for the other cases, in which each effect is considered alone, as well as no effect. The frequency coefficients are obtained for the lowest five vibration modes of arches with five combinations of classical boundary conditions, and various slenderness ratios and opening angles. The results show that the shear deformation and rotatory inertia effects are also very important as well as the axial extension effect, even if a slender shallow arch is considered. The discrepancies among the results of the five cases decrease, when opening angle increases for a constant radius and slenderness ratio. The effects of the boundary conditions and the slenderness ratio of the arch are investigated. The discrepancies among the results of the cases become much more important in higher modes. The mode shapes of a shallow arch are obtained for each case.
DETECTION OF DAMAGE LOCATIONS IN A BEAM USING THE WAVELET ANALYSIS
Authors: LEE Y. Y. , LIEW K. M.
Published: May 2003

This paper presents an effective way in damage detection of beam structures using the wavelet analysis along with the general beam solution. Two case studies are considered: (1) a clamped beam with a damage point of zero bending moment; and (2) a simply supported beam with a transverse open crack. The proposed method is capable of revealing the precise damage locations which is generally difficult to be identified using the standard eigenvalue analysis.
POST-CRITICAL BEHAVIOR OF MODERATELY THICK AXISYMMETRIC SHELLS: A SEQUENTIAL LIMIT ANALYSIS APPROACH
Authors: CORRADI LEONE , PANZERI NICOLA , POGGI CARLO
Published: May 2003

The design of some steel shells, like energy absorbers or bumpers, requires the knowledge of their behavior in large deformations. In this paper, the method of sequential limit analysis is presented and applied to axisymmetric shells in order to study their post-collapse response. Although the material behavior is assumed as rigid-plastic, results compare favorably with those produced by elastic-plastic incremental analyses and the procedure appears to be more efficient and numerically stable. Large displacement effects, both of stable and unstable nature, are implicitly accounted for by mesh updating.
NONLINEAR BUCKLING OF MARINE ELASTICA PIPES TRANSPORTING FLUID
Authors: CHUCHEEPSAKUL S. , MONPRAPUSSORN T.
Published: May 2003

This paper addresses the nonlinear buckling and post-buckling behavior of an extensible marine elastica pipe conveying fluid. The mathematical model employed in the nonlinear buckling analysis is developed based on the extensible elastica theory and the large strain formulation, so that the high extensibility of the pipe due to large axial strains is tackled thoroughly. The boundary value problem of the model is solved by the shooting method, and the numerical elastica solutions are obtained. For stability examination, the method of adjacent nonlinear equilibrium is exploited. It is revealed that the fundamental mode of nonlinear buckling of the pipe is reached when the pipe experiences either the critical top tension or the critical weight. Postbuckling behavior of the pipe is recognized to be unstable. The investigation is extended to studying various parameters that impinge on the limit states of the pipe. These parameters are the dimensionless quantities that relate to density of pipe material, densities of external and internal fluids, applied top tension, Poisson's ratio, slenderness ratio, vessel offset, seawater depth, current-drag coefficients, current velocity, and internal flow velocity.
BUCKLING AND VIBRATION OF STEPPED, SYMMETRIC CROSS-PLY LAMINATED RECTANGULAR PLATES
Authors: XIANG Y. , REDDY J. N.
Published: May 2003

This paper presents the exact buckling loads and vibration frequencies of multi-stepped symmetric cross-ply laminated rectangular plates having two opposite edges simply supported while the other two edges may have any combination of free, simply supported, and clamped conditions. An analytical method that uses the Lévy solution method and the domain decomposition technique is proposed to determine the buckling loads and natural frequencies of stepped laminated plates. Buckling and vibration solutions are obtained for symmetric cross-ply laminated rectangular plates having two-, three- and four-step thickness variations.
MULTI-MODE COUPLED BUFFETING ANALYSIS OF CABLE-STAYED BRIDGES
Authors: YANG YEONG-BIN , MAC SU-VAI , CHEN CHERN-HWA
Published: May 2003

A procedure for the spectral analysis of buffeting response of long span bridges under unsteady wind loads is developed, with emphasis placed on inclusion of the multi-mode vibrations. The effect of mean wind velocity is considered through the aerodynamic stiffness and damping matrices using the flutter derivatives, while the effect of buffeting through the auto- and cross-power spectral densities. Compared with the conventional approach, the present approach is featured by the fact that no selection has to be made concerning the dominant modes. It can be reasonably used in analyzing cable-stayed bridges of complex geometry or of asymmetric shape, such as the Kao-Ping-Hsi Bridge, where the conventional approach has its limitations. The numerical studies indicate that using the conventional approach, by which the coupling effect is ignored, may significantly overestimate the critical wind velocity, while underestimating the buffeting responses of cable-stayed bridges.
INTERACTIVE RETRIEVAL OF COLOR IMAGES
Authors: WORRING MARCEL , GEVERS THEO
Published: May 2003

Retrieval of color images has become an important application in recent years. We make a concise analysis of methodologies for interactive retrieval of color images. Two issues are of importance. First, the domain, which can be broad or narrow. Second, the search method, which can be object search, target search, category search or associative search. On the basis of these, we give complete guidelines for choosing and designing methods for interactive color image retrieval based on the domain and search goal characteristics.
LEARNING STRUCTURED VISUAL DETECTORS FROM USER INPUT AT MULTIPLE LEVELS
Authors: JAIMES ALEJANDRO , CHANG SHIH-FU
Published: May 2003

In this paper, we propose a new framework for the dynamic construction of structured visual object/scene detectors for content-based retrieval. In the Visual Apprentice, a user defines visual object/scene models via a multiple-level Definition Hierarchy: a scene consists of objects, which consist of object-parts, which consist of perceptual-areas, which consist of regions. The user trains the system by providing example images/videos and labeling components according to the hierarchy she defines (e.g., image of two people shaking hands contains two faces and a handshake). As the user trains the system, visual features (e.g., color, texture, motion, etc.) are extracted from each example provided, for each node of the hierarchy (defined by the user). Various machine learning algorithms are then applied to the training data, at each node, to learn classifiers. The best classifiers and features are then automatically selected for each node (using cross-validation on the training data). The process yields a Visual Object/Scene Detector (e.g., for a handshake), which consists of an hierarchy of classifiers as it was defined by the user. The Visual Detector classifies new images/videos by first automatically segmenting them, and applying the classifiers according to the hierarchy: regions are classified first, followed by the classification of perceptual-areas, object-parts and objects. We discuss how the concept of Recurrent Visual Semantics can be used to identify domains in which learning techniques such as the one presented can be applied. We then present experimental results using several hierarchies for classifying images and video shots (e.g., Baseball video, images that contain handhakes, skies, etc.). These results, which show good performance, demonstrate the feasibility and usefulness of dynamic approaches for constructing structured visual object/scene detectors from user input at multiple levels.
RECENT ADVANCES IN CONTENT-BASED VIDEO ANALYSIS
Authors: NGO CHONG-WAH , PONG TING-CHUEN , ZHANG HONG-JIANG
Published: May 2003

In this paper, we present major issues in video parsing, abstraction, retrieval and semantic analysis. We discuss the success, the difficulties and the expectations in these areas. In addition, we identify important opened problems that can lead to more sophisticated ways of video content analysis.

For video parsing, we discuss topics in video partitioning, motion characterization and object segmentation. The success in video parsing, in general, will have a great impact on video representation and retrieval. We present three levels of abstracting video content by scene, keyframe and key object representations. These representation schemes in overall serve as a good start for video retrieval. We then describe visual features, in particular motion, and similarity measures adopted for retrieval. Next, we discuss the recent computational approaches in bridging the semantic gap for video content understanding.
RELIABLE TRANSITION DETECTION IN VIDEOS: A SURVEY AND PRACTITIONER'S GUIDE
Authors: LIENHART RAINER
Published: May 2003

A large number of shot boundary detection, or equivalently, transition detection techniques have been developed in recent years. They all can be classified based on a few core concepts underlying the different detection schemes. This survey emphasizes those different core concepts underlying the different detection schemes for the three most widely used video transition effects: hard cuts, fades and dissolves. Representative of each concept one or a few very sound and thoroughly tested approaches are present in detail, while others are just listed. Whenever reliable performance numbers could be found in the literature, they are mentioned. Guidelines for practitioners in video processing are also given.
VIDEO CLASSIFICATION USING OBJECT TRACKING
Authors: DIMITROVA NEVENKA , AGNIHOTRI LALITHA , WEI GANG
Published: May 2003

Content description becomes important in the ubiquity of video content on the Web and consumer devices. Video classification is needed so that more appropriate description and search methods can be applied. This paper describes two methods for video content classification: a Nearest Neighbor (NN) method relying on domain knowledge and Hidden Markov Model (HMM) based method. Our approach stems from the observation that in different TV categories, there are different objects (e.g., face and text) trajectory patterns. Face and text tracking is applied to video segments to extract face and text trajectories. We used NN and HMM to classify a given video segment into predefined classes, e.g., commercial, news, situation comedy and soap. Our preliminary experimental results show classification accuracy of 75% for NN and over 80% for HMM based method on short video segments.
MPEG-7: A STANDARD FOR MULTIMEDIA CONTENT DESCRIPTION
Authors: PEREIRA FERNANDO , KOENEN ROB
Published: May 2003

Multimedia information is getting more abundant and the means to produce it are becoming a commodity, but finding and managing multimedia content is getting harder and harder. In 1996, MPEG (Moving Picture Experts Group) started a project formally named "Multimedia Content Description Interface", but better known as MPEG-7, acknowledging the need to efficiently and effectively describe and retrieve multimedia information and recognizing the substantial technological developments in the area of multimedia content description.

MPEG-7 sets a standard for multimedia description tools, notably so-called descriptors, description schemes, systems tools and a description definition language. MPEG-7 is generic in the sense that it is not specially designed or optimized for a particular application domain. It is however clear that image and video database applications are among its most important application domains.

This paper intends to overview the context, objectives, technical approach, workplan and achievements of the MPEG-7 standard. The first version and main body of this standard should be ready by July 2001.
MPEG-7 TEXTURE DESCRIPTORS
Authors: WU PENG , CHOI YANGLIM , RO YONG MAN , WON CHEE SUN
Published: May 2003

A texture description is useful in many applications including similarity based image search and browsing. We present here three texture descriptors that are being considered for the final committee draft of the ISO/MPEG-7 standard. A comprehensive overview of the syntax and semantics of these texture descriptors is provided. The Homogeneous Texture Descriptor (HTD) and the Edge Histogram Descriptor (EHD) are useful in similarity search. The HTD characterizes homogeneous texture regions and is also useful in texture classification and recognition. The EHD is applicable when the underlying texture is not homogeneous and can also be used in sketch based retrieval. In addition, a compact descriptor that facilitates browsing applications is also defined. These descriptors are selected after a highly competitive test and evaluation phase within the MPEG group and we briefly summarize the evaluation criteria, the datasets used and the experimental results.
AN EFFECTIVE APPROACH FOR SOLVING THE BINARY ASSIGNMENT PROBLEM WITH SIDE CONSTRAINTS
Authors: KOCHENBERGER GARY , GLOVER FRED , ALIDAEE BAHRAM
Published: May 2003

The binary assignment problem with a side constraint requiring the objective function to receive a specified value, which in general is an NP-hard problem, has been the focus of several papers in recent years. The current literature addresses various theoretical aspects of the problem, with a particular emphasis on a simplifying special case, but stops short of giving any computational experience. In this paper, we present a simple reformulation that enables the problem, and some of its extensions, to be solved by commonly available heuristic methods. We present preliminary computational experience with a Tabu search method that illustrates the effectiveness and computational robustness of the approach.