bluuebunny/crossref_metadata_2025 huggingface dataset:
Local zeta regularization and the scalar Casimir effect IV: The case of a rectangular box
Authors: Fermi Davide , Pizzocchero Livio
Published: February 2016

Applying the general framework for local zeta regularization proposed in Part I of this series of papers, we compute the renormalized vacuum expectation value of several observables (in particular, of the stress–energy tensor) for a massless scalar field confined within a rectangular box of arbitrary dimension.
Multi-branch structure for electrically charged four-pole axially symmetric system of solutions
Authors: Soltanian Amin , Teh Rosy , Wong Khai-Ming
Published: February 2016

Dyon solutions with axial symmetry in Yang–Mills–Higgs theory, including monopole–antimonopole pairs (MAP), monopole–antimonopole chains (MAC) and vortex-rings are introduced previously. The previously studied cases include at most a bifurcation for MAP systems and two for MAC dyon solutions. Here, for the case of [Formula: see text]-winding number [Formula: see text], a rich set of solutions including nine branches and four bifurcations, has been obtained for electrically charged four-pole MAC solutions. Also, the transition between two different charge configurations at a lower energy bifurcating branch is detected for the first time. This study also improves and completes some aspects of a previous study on the electrically neutral case. In the case of [Formula: see text], in addition to previously found bifurcation, another bifurcation at small values of Higgs self-coupling constant [Formula: see text], has been obtained here.
Interaction-free generation of orbital angular momentum entanglement
Authors: Chen Yuanyuan , Jiang Dong , Gu Xuemei , Xie Ling , Chen Lijun
Published: February 2016

Due to the infinite range of possibly achievable degrees of freedom, orbital angular momentum (OAM) can tremendously increase the capacity of communication system. Here, we propose a scheme to generate OAM entanglement by using interaction-free measurement (IFM). As the superposition state of the quantum absorption object is not changed after IFM, our scheme can be extended to multiparty easily. The numerical analysis results show that the fidelity of generated OAM entanglement can be arbitrarily close to unity. Besides, the implementation issues are also discussed to evaluate the feasibility in experiment. This OAM entanglement with multiple degrees of freedom will play a key role in distributed entanglement computing and efficient quantum communication.
A facile synthesis of poly(aniline-co-o-bromoaniline) copolymer: Characterization and application as semiconducting material
Authors: Mahudeswaran A. , Vivekanandan J. , Vijayanand P. S. , Kojima T. , Kato S.
Published: February 2016

Poly(aniline-co-o-bromoaniline) (p(an-co-o-BrAn)) copolymer has been synthesized using chemical oxidation method in the hydrochloric acid medium. Copolymerization of aniline with o-bromoaniline of different compositions, such as 1:1, 1:2, 2:1, 1:3 and 3:1 molar ratios were prepared. The synthesized copolymer is soluble in polar solvents like dimethyl sulphoxide (DMSO), dimethyl formamide (DMF), Tetrahydrofuran (THF) and 1-methyl 2-pyrrolidone (NMP). The copolymer is analyzed by various characterization techniques, such as FTIR, UV–Visible (UV–Vis) spectroscopy, X-ray diffraction (XRD), conductivity, Differential scanning calorimetry (DSC) and scanning electron microscopy (SEM). FTIR spectrum confirms the characteristic peaks of the copolymer containing benzenoid and quinoid ring stretching. UV spectrum reveals the formation of [Formula: see text]–[Formula: see text] transition and [Formula: see text]–[Formula: see text] transition between the energy levels. XRD peaks reveal that the copolymer possesses amorphous nature. Morphological study reveals that the agglomerated particles form globular structure and size of the each particle is about 100 nm. The electrical conductivity of the copolymers is found in the range of [Formula: see text]. These organic semiconductor materials can be used to fabricate thinner and cheaper environmental friendly optoelectronic devices that will replace the conventional inorganic semiconductors.
Coherence resonance in the two-dimensional neural map driven by non-Gaussian colored noise
Authors: Li Dongxi , Hu Bing , Wang Jia , Jing Yingchuan , Hou Fangmei
Published: February 2016

Based on the two-dimensional (2D) neural map, we investigate the impacts of non-Gaussian colored noise on the firing activity of discrete system. Taking the coherence parameter R to measure the regularity of firing behavior, it is demonstrated that coherence parameter R has a pronounced minimum value with the noise intensity and the correlation time of non-Gaussian colored noise, which is the so-called phenomenon of coherence resonance (CR). Besides, the firing activity is not sensitive to the non-Gaussian parameter which determines the departure from the Gaussian distribution when the correlation time is large enough.
Comparison of decoherence and Zeno dynamics from the context of weak measurement for a two-level atom traversing through squeezed vacuum
Authors: Bhattacharya Samyadeb
Published: February 2016

Decay parameter of coherence and population inversion are calculated from the master equation of a two-level atom tunneling through a squeezed vacuum. Using those parameters, the timescales for decoherence and Zeno effect are calculated in the weak measurement scheme. By comparing those timescales, a certain condition on the relevant experimental parameters has been found for sustainable coherent dynamics.
Acoustic emission study of deformation behavior of nacre
Authors: Luo Shunfei , Luo Hongyun , Han Zhiyuan
Published: February 2016

A study on the acoustic emission (AE) characteristics during deformation of nacre material was performed. We found that intermittent AE events are generated during nacre deformation. These avalanches may be attributed to microfracture events of the aragonite (CaCO3) nano-asperities and bridges during tablet sliding. These events show several critical features, such as the power-law distributions of the avalanche sizes and interval. These results suggest that the underlying fracture dynamics during nacre deformation display a self-organized criticality (SOC). The results also imply that the disorder and long-range correlation between local microfracture events may play important roles in nacre deformation.
Fast phase transition of water molecules in a defective carbon nanotube under an electric field
Authors: Meng Xianwen , Huang Jiping
Published: February 2016

We utilize molecular dynamics simulations to study the effect of an electric field on the permeation of water molecules through a defective single-walled carbon nanotube (DSWCNT). Compared with a perfect single-walled carbon nanotube (PSWCNT), the behaviors of water molecules respond more quickly under the same electric field in a DSWCNT. Wet–dry phase transition of water molecules occurs when the electric field reaches 0.32 V/nm, which is much lower than the case of the PSWCNT. Besides, the critical electric field is affected by the number of defects. These results pave a way for designing fast wet–dry transition devices and provide a new insight into water permeation through a defective nanochannel.
Nonclassical properties and teleportation in the two-mode photon-added displaced squeezed states
Authors: Hoai Nguyen Thi Xuan , Duc Truong Minh
Published: February 2016

In this paper, we study the nonclassical properties and find out the effect of photon addition on these properties as well as the process of teleportation in the two-mode photon-added displaced squeezed (TMPADS) states. We derive the analytic expressions of the Wigner function, the photon number distribution and the intermode photon antibunching for these states. We show that photon addition operation not only makes the Wigner function become negative but also leads to increase the degree of antibunching. The peak of the photon number distribution becomes flatter and shifts to the greater number of photons by adding photons to both modes simultaneously. Furthermore, it is proved that the degree of intermodal entanglement becomes bigger and bigger through increasing the number of photons added to both modes. As expected, when using these states as an entanglement resource to teleport a state, the average fidelity of teleportation process is also improved by increasing the number of added photons.
The coating design of phase-shifting reflector array with high reflectance and specified reflection phase shifts for static Michelson interferometer
Authors: Zhang Xuanni , Zhang Hui , Wang Yijun
Published: February 2016

The optical Doppler Michelson imaging interferometer is widely used for wind measurements. Four interferograms obtained simultaneously are needed to immune to environmental disturbances. Thus, a static and divided mirror Michelson interferometer is proposed. Its highlight is the phase-shifting reflector array, which divides one mirror into four quadrants coated by different multilayer films with high reflectance, specified phase steps [Formula: see text] and little polarization effects. By combining analytical and empirical method, four coatings are designed with software TFCalc. The simulated results showed good agreement with the desired optical properties. Due to the limitation of the optical material and function of the software TFCalc, there are some design errors within tolerance.
A Bottleneck Matching Problem with Edge-Crossing Constraints
Authors: Carlsson John Gunnar , Armbruster Benjamin , Rahul Saladi , Bellam Haritha
Published: February 2016

Motivated by a crane assignment problem, we consider a Euclidean bipartite matching problem with edge-crossing constraints. Specifically, given [Formula: see text] red points and [Formula: see text] blue points in the plane, we want to construct a perfect matching between red and blue points that minimizes the length of the longest edge, while imposing a constraint that no two edges may cross each other. We show that the problem cannot be approximately solved within a factor less than 1:277 in polynomial time unless [Formula: see text]. We give simple dynamic programming algorithms that solve our problem in two special cases, namely (1) the case where the red and blue points form the vertices of a convex polygon and (2) the case where the red points are collinear and the blue points lie to one side of the line through the red points.
Placing Two Axis-Parallel Squares to Maximize the Number of Enclosed Points
Authors: Mahapatra Priya Ranjan Sinha , Goswami Partha P. , Das Sandip
Published: February 2016

Let [Formula: see text] be a set of [Formula: see text] input points in the plane. An algorithm is proposed to place a pair of axis-parallel unit squares, either intersecting with no points in the intersection zone or disjoint, together enclosing the maximum number of input points. The time and space complexities of the algorithm are both [Formula: see text]. In case the input points are allowed to lie inside the intersection zone of two intersecting axis-parallel unit squares, two such unit squares enclosing the maximum number of input points can be placed in [Formula: see text] time using [Formula: see text] space.
OPTIMAL EXECUTION COST FOR LIQUIDATION THROUGH A LIMIT ORDER MARKET
Authors: CHEVALIER ETIENNE , VATH VATHANA LY , SCOTTI SIMONE , ROCH ALEXANDRE
Published: February 2016

We study the problem of optimally liquidating a large portfolio position in a limit-order market. We allow for both limit and market orders and the optimal solution is a combination of both types of orders. Market orders deplete the order book, making future trades more expensive, whereas limit orders can be entered at more favorable prices but are not guaranteed to be filled. We model the bid-ask spread with resilience by a jump process, and the market-order arrival process as a controlled Poisson process. The objective is to minimize the execution cost of the strategy. We formulate the problem as a mixed stochastic continuous control and impulse problem for which the value function is shown to be the unique viscosity solution of the associated variational inequalities. We conclude with a calibration of the model on recent market data and a numerical implementation.
Entropy NOR: Early Functional Completeness in Entropy Networks
Authors: jesse Forrest Fabian , Miao Zhenjiang , Li Weidong
Published: February 2016

Linking together two directional entropy disequilibriums, NOR functionality can be found. The entropy NOR gate presented is constructed of discrete observations and so is very small, emerging at the earliest stages of complexity. The gate is based on the axiom that an observer increases in entropy as it receives information from what it is observing.
A Study of Cyber Security Awareness in Educational Environment in the Middle East
Authors: Al-Janabi Samaher , Al-Shourbaji Ibrahim
Published: February 2016

Information security awareness can play an important role in facing cyber-attacks by intruders. The main goal of this paper is to analyse the information security awareness among academic staff, researchers, undergraduate students and employee within educational environments in the Middle East in an attempt to understand the level of awareness of information security, the associated risks and overall impact on the institutions. The results reveal that the participants do not have the requisite knowledge and understanding of the importance of information security principles and their practical application in their day-to-day work. This situation can however be corrected through comprehensive awareness and training programs as well as adopting all the necessary safety measures at all levels of the institution to ensure that the students, academic staff and employees are trustworthy, technology savvy and keep their data safe. Without such training programs and awareness, there will be negative consequences on IT systems and their application usage, as well as on users’ personal security now and in the future. From the weaknesses identified in this survey, some essential recommendations are put forward to remedy the situation.
Explicit constructions of all separable two-qubits density matrices and related problems for three-qubits systems
Authors: Ben-Aryeh Y. , Mann A.
Published: February 2016

Explicitly separable density matrices are constructed for all separable two-qubits states based on Hilbert–Schmidt (HS) decompositions. For density matrices which include only two-qubits correlations the number of HS parameters is reduced to 3 by using local rotations, and for two-qubits states which include single qubit measurements, the number of parameters is reduced to 4 by local Lorentz transformations. For both cases, we related the absolute values of the HS parameters to probabilities, and the outer products of various Pauli matrices were transformed to pure state density matrices products. We discuss related problems for three-qubits. For n-qubits correlation systems ([Formula: see text]) the sufficient condition for separability may be improved by local transformations, related to high order singular value decompositions (SVDs).
Particle Filter-Based SLAM from Localization Viewpoint
Authors: Havangi Ramazan
Published: February 2016

In order to enhance consistency in simultaneous localization and mapping (SLAM), in this paper, this problem is considered as a solely localization problem in the presence of unknown parameters. In this approach, the proposal distribution is generated based on marginal extended particle filter and static map is considered as a parametric estimation that is estimated by maximum likelihood techniques. Significant improvement of the filtering result from this viewpoint is demonstrated in terms of estimation performance and consistency. Some simulations and experiments are presented to evaluate the algorithm’s performance in comparison to conventional methods.
Quasi-Static Crack Propagation Modeling Using Shape-Free Hybrid Stress-Function Elements with Drilling Degrees of Freedom
Authors: Cen Song , Bao Yi , Li Chen-Feng
Published: February 2016

A new plane shape-free multi-node singular hybrid stress-function (HS-F) element with drilling degrees of freedom, which can accurately capture the stress intensity factors at the crack tips, is developed. Then, a quasi-static 2D crack propagation modeling strategy is established by combination of the new singular element and a shape-free 4-node HS-F plane element with drilling degrees of freedom proposed recently. Only simple remeshing with an unstructured mesh is needed for each simulation step. Numerical results show that the proposed scheme is an effective and robust technique for dealing with the crack propagation problems.
An Essentially Nonoscillatory Spectral Deferred Correction Method for Hyperbolic Problems
Authors: Kadioglu Samet Y.
Published: February 2016

We present a computational method based on the spectral deferred corrections (SDC) time integration technique and the essentially nonoscillatory (ENO) finite volume method for hyperbolic problems. The SDC technique is used to advance the solutions in time with high-order of accuracy. The ENO method is used to define high-order cell edge quantities that are then used to evaluate numerical fluxes. The coupling of the SDC method with a high-order finite volume method (piece-wise parabolic method (PPM)) is first carried out by Layton et al. [J. Comput. Phys. 194(2) (2004) 697]. Issues about this approach have been addressed and some improvements have been added to it in Kadioglu et al. [J. Comput. Math. 1(4) (2012) 303]. Here, we investigate the implications when the PPM method is replaced with the well-known ENO method. We note that the SDC-PPM method is fourth-order accurate in time and space. Therefore, we kept the order of accuracy of the ENO procedure as fourth-order in order to be able to make a consistent comparison between the two approaches (SDC-ENO versus SDC-PPM). We have tested the new SDC-ENO technique by solving smooth and nonsmooth hyperbolic problems. Our numerical results indicate that the fourth-order of accuracy in both space and time has been achieved for smooth problems. On the other hand, the new method performs very well when it is applied to nonlinear problems that involve discontinuous solutions. In other words, we have obtained highly resolved discontinuous solutions with essentially no-oscillations at or around the discontinuities.
Oxygen atom transfer reactions from sterically encumbered brominated (oxo)manganese(V) corroles to styrene
Authors: Mahmood Mian HR , Wang Hua-Hua , Liu Hai-Yang , Chang Chi-Kwong
Published: February 2016

Seven A3- and trans-A2B manganese(III) corroles (1–7-Mn) differing widely in their electronic and steric features were synthesized and transformed to their corresponding [Formula: see text]-brominated manganese(III) corroles derivatives (1a–7a-Mn). Their corresponding (oxo)manganese(V) corroles 1–7-Mn(oxo) and 1a–7a-Mn(oxo) were further prepapred by treating with iodosylbenzene (PhIO). The reactivity for the oxygen atom transfer from 1–7-Mn(oxo) to styrene followed the order of 1-Mn(oxo) > 2-Mn(oxo) > 7-Mn(oxo) > 4-Mn(oxo) > 3-Mn(oxo) > 6-Mn(oxo) [Formula: see text]5-Mn(oxo). The same pattern was observed for their [Formula: see text]-brominated analogs 1a–7a-Mn(oxo), albeit their reactivity was remarkably higher. The steric protection of [Formula: see text] moiety by ortho–ortho′-dibromophenyl substituents was found to enhance the stability of (oxo)manganese(V) corroles significantly.
Solid-state porphyrin interactions with oppositely charged peripheral groups
Authors: Scheldt W. Robert , Cheng Beisong , Oliver Allen G. , Goodwin John A.
Published: February 2016

The crystallization and the crystal and molecular structure of a very slightly soluble electrostatically interacting pair of porphyrins is described. The tetra-anion 5,10,15,20-tetrakis-(4-sulfonatophenyl)-21,23H-porphyrin [H2TPPSO3][Formula: see text] and the tetra-cation 5,10,15,20-tetra([Formula: see text]-methylpyridyl)21H,23H-porphyrin [H2TMePyP][Formula: see text] are found to form an alternating one-dimensional stack that is stabilized by electrostatic interactions between the porphyrin rings but also by [Formula: see text] interactions between all substituted phenyl rings in the ensemble. The resulting interactions between the porphyrins is exceptionally tight.
A metalloporphyrinic compound with a high selectivity for N2 and CO2 separation
Authors: Zhang Xian , Cheng Wen-Tong , Suenobu Tomoyoshi , Fukuzumi Shunichi , Wang Ming-Sheng , Guo Guo-Cong
Published: February 2016

Using a hydrothermal reaction of SmCl3•6H2O, ZnBr2 and TPPS, a crystalline metalloporphyrinic compound (MPC), [SmZn(TPPS)H3O][Formula: see text]•2[Formula: see text]H2O (1), was synthesized. The crystal structure of the MPC exhibits a condensed and robust 3-D porous open framework. We studied the adsorption and desorption isotherms for N2, H2 and CO2 conducted at 77 K and 273 K. They show different isotherms such as Type I, II and III isotherm behaviors. We found that low temperature is propitious for the title complex to adsorb more H2, but less N2. Compound 1 showed remarkably high selectivity for CO2–N2 separation, and good thermal stability. The temperature dependent magnetic susceptibility shows an antiferromagnetic-like behavior for 1.
INNOVATIVE BRAND COMMUNITY MEMBERS AND THEIR WILLINGNESS TO SHARE IDEAS WITH COMPANIES
Authors: NØRSKOV SLADJANA , ANTORINI YUN MI , JENSEN MORTEN BERG
Published: February 2016

With the aim of contributing to the existing knowledge of brand community members and their willingness to share ideas, we investigate whether and how brand community innovators’ (i) lead user characteristics, (ii) brand community identification, (iii) brand knowledge, (iv) brand loyalty and (v) preferences regarding the brand owner’s interference in community activities influence their willingness to share their ideas with the company. In contrast to earlier studies, which inquired into brand community members’ intentions to share their ideas [see Füller, J, K Matzler and M Hoppe (2008). Brand community members as a source of innovation. Journal of Product Innovation Management, 25, 608–619], we studied members who had already innovated and were actively involved in innovation processes.

Using a survey of the Adult Fans of Lego (AFOL) community, we found that brand community members’ willingness to share their ideas is positively related to the ahead of the trend (AT) dimension of lead user characteristics, brand community identification and brand loyalty. Interference by the company in community activities also plays a role. Surprisingly, the brand community innovators perceive this role oppositely to what prior research on firm-hosted and open-source communities suggests. This study extends our knowledge of brand communities by demonstrating how brand community innovators’ interpersonal contexts, personal traits and brand perceptions may promote or demote willingness to share.
Mean First Passage Time in Single File Dynamics
Authors: Flomenbom Ophir
Published: February 2016

We derive the general scaling law of the mean first passage time (MFPT) in single file dynamics; the process where many real particles move in a channel of length [Formula: see text] with absorbing boundaries, where the particles and the channel have about the same cross section. We derive the relation [Formula: see text], here we compute the MFPT when the channel is free (all particles are absorbed, where the average is over many trajectories), [Formula: see text] is the number of particles in the channel at initiation, [Formula: see text] is the many-particle effect and the quantity MFPT[Formula: see text] is the MFPT of the free particle. When at initiation the density is fixed in basic files [Formula: see text] and therefore e.g. [Formula: see text] (basic stochastic dynamics). We also compute the MFPT in diverse files; for example, in a file with heterogeneous particles, in deterministic files, in slow files and in files with long-range interactions. When the particle density is not fixed yet scales with 1/length from the origin, [Formula: see text]; yet, interactions might increase (attractive) or decrease (repulsive) the many-particle effect relative to [Formula: see text]. In slow files, [Formula: see text] (in the number of jumps). We explain these valuable results with various methods and approaches, e.g., we derive a general mapping from the mean square displacement scaling law to the MFPT scaling law. We also connect the results with real life activities.

Special Issue Comments: Mean first passage scaling law in single file dynamics and various particular results in files are derived in this project. The project is related to the Special Issue projects about heterogeneous files and slow files,[Formula: see text] expansions in files,[Formula: see text] files with force[Formula: see text] and the first passage time in files.[Formula: see text]
Combining hazard rates with the CreditGrades model: A hybrid method to value CDS contracts
Authors: Lee Chih-Wei , Kuo Cheng-Kun
Published: February 2016

In this paper, we propose a hybrid method that combines a hazard rate model with the CreditGrades model to value credit default swap (CDS) contracts. The CreditGrades model is considered an industry benchmark for analyzing credit derivatives. The hybrid method makes use of the default probability generated by the CreditGrades model to determine the hazard rate specific to the bond issuing firm. In this way, the hybrid method is empirically shown to produce better CDS forecast.
Short maturity options for Azéma–Yor martingales
Authors: Zhu Lingjiong
Published: February 2016

A class of positive Azéma–Yor martingales was first introduced in the option pricing context by Peter Carr (2014). In this paper, we present a rigorous study of the short maturity asymptotics for Asian, upper barrier, lower barrier and European options with continuous-time averaging, under the assumption that the underlying asset follows a Azéma–Yor martingale.
Algorithm 955
Authors: Giles Michael B.
Published: February 2016

New approximations for the inverse of the incomplete gamma function are derived, which are used to develop efficient evaluations of the inverse Poisson cumulative distribution function. An asymptotic approximation based on the standard Normal approximation is particularly good for CPUs with MIMD cores, while for GPUs and other hardware with vector units, a second asymptotic approximation based on Temme's approximation of the incomplete gamma function is more efficient due to conditional branching within each vector. The accuracy and efficiency of the software implementations is assessed on both CPUs and GPUs.
A Novel Classification Framework for Evaluating Individual and Aggregate Diversity in Top-N Recommendations
Authors: Moody Jennifer , Glass David H.
Published: February 2016

The primary goal of a recommender system is to generate high quality user-centred recommendations. However, the traditional evaluation methods and metrics were developed before researchers understood all the factors that increase user satisfaction. This study is an introduction to a novel user and item classification framework. It is proposed that this framework should be used during user-centred evaluation of recommender systems and the need for this framework is justified through experiments. User profiles are constructed and matched against other users’ profiles to formulate neighbourhoods and generate top-N recommendations. The recommendations are evaluated to measure the success of the process. In conjunction with the framework, a new diversity metric is presented and explained. The accuracy, coverage, and diversity of top-N recommendations is illustrated and discussed for groups of users. It is found that in contradiction to common assumptions, not all users suffer as expected from the data sparsity problem. In fact, the group of users that receive the most accurate recommendations do not belong to the least sparse area of the dataset.
Sampling Exactly from the Normal Distribution
Authors: Karney Charles F. F.
Published: February 2016

An algorithm for sampling exactly from the normal distribution is given. The algorithm reads some number of uniformly distributed random digits in a given base and generates an initial portion of the representation of a normal deviate in the same base. Thereafter, uniform random digits are copied directly into the representation of the normal deviate. Thus, in contrast to existing methods, it is possible to generate normal deviates exactly rounded to any precision with a mean cost that scales linearly in the precision. The method performs no extended precision arithmetic, calls no transcendental functions, and uses no floating point arithmetic whatsoever; it uses only simple integer operations. It can easily be adapted to sample exactly from the discrete normal distribution whose parameters are rational numbers.
Testing Matrix Function Algorithms Using Identities
Authors: Deadman Edvin , Higham Nicholas J.
Published: February 2016

Algorithms for computing matrix functions are typically tested by comparing the forward error with the product of the condition number and the unit roundoff. The forward error is computed with the aid of a reference solution, typically computed at high precision. An alternative approach is to use functional identities such as the “round-trip tests”
e

log
A

=
A
and (
A

1/
p

)

p

=
A
, as are currently employed in a SciPy test module. We show how a linearized perturbation analysis for a functional identity allows the determination of a maximum residual consistent with backward stability of the constituent matrix function evaluations. Comparison of this maximum residual with a computed residual provides a necessary test for backward stability. We also show how the actual linearized backward error for these relations can be computed. Our approach makes use of Fréchet derivatives and estimates of their norms. Numerical experiments show that the proposed approaches are able both to detect instability and to confirm stability.
Can We Group Storage? Statistical Techniques to Identify Predictive Groupings in Storage System Accesses
Authors: Wildani Avani , Miller Ethan L.
Published: February 2016

Storing large amounts of data for different users has become the new normal in a modern distributed cloud storage environment. Storing data successfully requires a balance of availability, reliability, cost, and performance. Typically, systems design for this balance with minimal information about the data that will pass through them. We propose a series of methods to derive groupings from data that have predictive value, informing layout decisions for data on disk.

Unlike previous grouping work, we focus on dynamically identifying groupings in data that can be gathered from active systems in real time with minimal impact using spatiotemporal locality. We outline several techniques we have developed and discuss how we select particular techniques for particular workloads and application domains. Our statistical and machine-learning-based grouping algorithms answer questions such as “What can a grouping be based on?” and “Is a given grouping meaningful for a given application?” We design our models to be flexible and require minimal domain information so that our results are as broadly applicable as possible. We intend for this work to provide a launchpad for future specialized system design using groupings in combination with caching policies and architectural distinctions such as tiered storage to create the next generation of scalable storage systems.
ShearLab 3D
Authors: Kutyniok Gitta , Lim Wang-Q , Reisenhofer Rafael
Published: February 2016

Wavelets and their associated transforms are highly efficient when approximating and analyzing one-dimensional signals. However, multivariate signals such as images or videos typically exhibit curvilinear singularities, which wavelets are provably deficient in sparsely approximating and also in analyzing in the sense of, for instance, detecting their direction. Shearlets are a directional representation system extending the wavelet framework, which overcomes those deficiencies. Similar to wavelets, shearlets allow a faithful implementation and fast associated transforms. In this article, we will introduce a comprehensive carefully documented software package coined ShearLab 3D (www.ShearLab.org) and discuss its algorithmic details. This package provides MATLAB code for a novel faithful algorithmic realization of the 2D and 3D shearlet transform (and their inverses) associated with compactly supported universal shearlet systems incorporating the option of using CUDA. We will present extensive numerical experiments in 2D and 3D concerning denoising, inpainting, and feature extraction, comparing the performance of ShearLab 3D with similar transform-based algorithms such as curvelets, contourlets, or surfacelets. In the spirit of reproducible research, all scripts are accessible on www.ShearLab.org.
A Sparse Symmetric Indefinite Direct Solver for GPU Architectures
Authors: Hogg Jonathan D. , Ovtchinnikov Evgueni , Scott Jennifer A.
Published: February 2016

In recent years, there has been considerable interest in the potential for graphics processing units (GPUs) to speed up the performance of sparse direct linear solvers. Efforts have focused on symmetric positive-definite systems for which no pivoting is required, while little progress has been reported for the much harder indefinite case. We address this challenge by designing and developing a sparse symmetric indefinite solver SSIDS. This new library-quality

LDL
T

factorization is designed for use on GPU architectures and incorporates threshold partial pivoting within a multifrontal approach. Both the factorize and the solve phases are performed using the GPU. Another important feature is that the solver produces bit-compatible results. Numerical results for indefinite problems arising from a range of practical applications demonstrate that, for large problems, SSIDS achieves performance improvements of up to a factor of 4.6 × compared with a state-of-the-art multifrontal solver on a multicore CPU.
Arabic Cross-Language Information Retrieval
Authors: Elayeb Bilel , Bounhas Ibrahim
Published: February 2016

Cross-language information retrieval (CLIR) deals with retrieving relevant documents in one language using queries expressed in another language. As CLIR tools rely on translation techniques, they are challenged by the properties of highly derivational and flexional languages like Arabic. Much work has been done on CLIR for different languages including Arabic. In this article, we introduce the reader to the motivations for solving some problems related to Arabic CLIR approaches. The evaluation of these approaches is discussed starting from the 2001 and 2002 TREC Arabic CLIR tracks, which aim to objectively evaluate CLIR systems. We also study many other research works to highlight the unresolved problems or those that require further investigation. These works are discussed in the light of a deep study of the specificities and the tasks of Arabic information retrieval (IR). Particular attention is given to translation techniques and CLIR resources, which are key issues challenging Arabic CLIR. To push research in this field, we discuss how a new standard collection can improve Arabic IR and CLIR tracks.
A C2RTL Framework Supporting Partition, Parallelization, and FIFO Sizing for Streaming Applications
Authors: Zhang Daming , Li Shuangchen , Liu Yongpan , Hu Xiaobo Sharon , He Xinyu , Zhang Yining , Zhang Pei , Yang Huazhong
Published: February 2016

Developing circuits for streaming applications written in C (or its variants) can benefit greatly from C-to-RTL (C2RTL) synthesis. Yet, most existing C2RTL tools lack system-level options to trade off various design constraints, such as delay and area. This article introduces a systematic way to accomplish C2RTL synthesis for streaming applications containing thousands of lines of C (or its variants) codes. Synthesizing circuits for such large applications presents serious challenges for existing C2RTL tools. Specifically, the proposed approach determines simultaneously the number of pipeline stages and the number of times that each functional block is duplicated in each pipeline stage. A mixed integer linear programming-based solution is formulated for obtaining the optimal solution. Furthermore, a heuristic algorithm is developed for large-scale problems. To accommodate the differences of the data rates between the adjacent hardware modules, first-in-first-out (FIFO) buffers are indispensable, but their overheads are nonnegligible. A parallelism-aware FIFO sizing method is also introduced to determine the optimal sizes of FIFOs. Experimental results on seven real-world applications demonstrate that the algorithms in the synthesis flow can make effective design trade-offs and find superior solutions in a short time compared with existing approaches. Furthermore, the algorithms achieve optimal results in most cases with subsecond running time.
Parameterized Decay Model for Information Retrieval
Authors: Paik Jiaul H.
Published: February 2016

This article proposes a term weighting scheme for measuring query-document similarity that attempts to explicitly model the dependency between separate occurrences of a term in a document. The assumption is that, if a term appears once in a document, it is more likely to appear again in the same document. Thus, as the term appears again and again, the information content of the subsequent occurrences decreases gradually, since they are more predictable. We introduce a parameterized decay function to model this assumption, where the initial contribution of the term can be determined using any reasonable term discrimination factor. The effectiveness of the proposed model is evaluated on a number of recent web test collections of varying nature. The experimental results show that the proposed model significantly outperforms a number of well known retrieval models including a recently proposed strong Term Frequency and Inverse Document Frequency (TF-IDF) model.
Quality-Based Online Data Reconciliation
Authors: Abboura Asma , Sahri Soror , Baba-Hamed Latifa , Ouziri Mourad , Benbernou Salima
Published: February 2016

One of the main challenges in data matching and data cleaning, in highly integrated systems, is
duplicates detection
. While the literature abounds of approaches detecting duplicates corresponding to the same real-world entity, most of these approaches tend to eliminate duplicates (wrong information) from the sources, hence leading to what is called
data repair.
In this article, we propose a framework that automatically detects duplicates at query time and effectively identifies the consistent version of the data, while keeping inconsistent data in the sources. Our framework uses matching dependencies (MDs) to detect duplicates through the concept of data reconciliation rules (DRR) and conditional function dependencies (CFDs) to assess the quality of different attribute values. We also build a duplicate reconciliation index (
DRI
), based on clusters of duplicates detected by a set of DRRs to speed up the online data reconciliation process. Our experiments of a real-world data collection show the efficiency and effectiveness of our framework.
Optimization of 3D Digital Microfluidic Biochips for the Multiplexed Polymerase Chain Reaction
Authors: Li Zipeng , Ho Tsung-Yi , Chakrabarty Krishnendu
Published: February 2016

A digital microfluidic biochip (DMFB) is an attractive technology platform for revolutionizing immunoassays, clinical diagnostics, drug discovery, DNA sequencing, and other laboratory procedures in biochemistry. In most of these applications, real-time polymerase chain reaction (PCR) is an indispensable step for amplifying specific DNA segments. To reduce the reaction time to meet the requirement of “real-time” applications, multiplexed PCR is widely utilized. In recent years, three-dimensional (3D) DMFBs that integrate photodetectors (i.e., cyberphysical DMFBs) have been developed, which offer the benefits of smaller size, higher sensitivity, and faster result generations. However, current DMFB design methods target optimization in only two dimensions, thus ignoring the 3D two-layer structure of a DMFB. Furthermore, these techniques ignore practical constraints related to the interference between on-chip device pairs, the performance-critical PCR thermal loop, and the physical size of devices. Moreover, some practical issues in real scenarios are not stressed (e.g., the avoidance of the cross-contamination for multiplexed PCR). In this article, we describe an optimization solution for a 3D DMFB and present a three-stage algorithm to realize a compact 3D PCR chip layout, which includes: (i) PCR thermal-loop optimization, (ii) 3D global placement based on Strong-Push-Weak-Pull (SPWP) model, and (iii) constraint-aware legalization. To avoid cross-contamination between different DNA samples, we also propose a Minimum-Cost-Maximum-Flow-based (MCMF-based) method for reservoir assignment. Simulation results for four laboratory protocols demonstrate that the proposed approach is effective for the design and optimization of a 3D chip for multiplexed real-time PCR.
Modeling Monolingual Character Alignment for Automatic Evaluation of Chinese Translation
Authors: Li Maoxi , Wang Mingwen , Li Hanxi , Xu Fan
Published: February 2016

Automatic evaluation of machine translations is an important task. Most existing evaluation metrics rely on matching the same word or letter
n
-grams. This strategy leads to poor results on Chinese translations because one has to rely merely on matching identical characters. In this article, we propose a new evaluation metric that allows different characters with the same or similar meaning to match. An Indirect Hidden Markov Model (IHMM) is proposed to align the Chinese translation with human references at the character level. In the model, the emission probabilities are estimated by character similarity, including character semantic similarity and character surface similarity, and transition probabilities are estimated by a heuristic distance-based distortion model. When evaluating the submitted output of English-to-Chinese translation systems in the IWSLT’08 CT-EC and NIST’08 EC tasks, the experimental results indicate that the proposed metric has a significantly better correlation with human evaluation than the state-of-the-art machine translation metrics (i.e., BLEU, Meteor Universal, and TESLA-CELAB). This study shows that it is important to allow different characters to match in the evaluation of Chinese translations and that the IHMM is a reasonable approach for the alignment of Chinese characters.
Theory and Application of Delay Constraints in Arbiter PUF
Authors: Chatterjee Urbi , Chakraborty Rajat Subhra , Kapoor Hitesh , Mukhopadhyay Debdeep
Published: February 2016

Physically Unclonable Function (PUF) circuits are often vulnerable to mathematical
model-building attacks
. We theoretically quantify the advantage provided to an adversary by any training dataset expansion technique along the lines of security analysis of cryptographic hash functions. We present an algorithm to enumerate certain sets of delay constraints for the widely studied
Arbiter PUF
(APUF) circuit, then demonstrate how these delay constraints can be utilized to expand the set of known Challenge--Response Pairs (CRPs), thus facilitating model-building attacks. We provide experimental results for Field Programmable Gate Array (FPGA)--based APUF to establish the effectiveness of the proposed attack.
Intensional Couplings in Variable-Structure Models
Authors: Steiniger Alexander , Uhrmacher Adelinde M.
Published: February 2016

In modular, hierarchical modeling, couplings (connections) describe and constrain the communication, and thus interaction, between model components. Defining couplings between a large set of components in an extensional manner—listing all existing couplings individually—often proves to be rather tedious. Moreover, if models change their structure, that is, composition and interaction patterns and, in some cases, even their interfaces during simulation, questions about the consistency of the couplings arise. For instance, an extensionally defined coupling may refer to a model that no longer exists. Instead, an intensional coupling definition, based on attributes of the components to couple and dynamically translated into concrete couplings during simulation, promises to alleviate these problems. We propose a concept that combines a flexible, yet expressive, definition of couplings that rests on component interfaces announcing attributes of interest. However, intensional couplings come at a price, as they need to be translated during simulation; in variable-structure models, this translation has to happen frequently. We illuminate our concept based on a revision of the modeling formalism Multilevel Discrete Event System Specification (
ML
-
DEVS
). Developed for multilevel modeling and simulation,
ML
-
DEVS
exhibits another alternative to intensional couplings, that is, sharing parts of model states for up- and downward causation. The intricate interplay between these different types of couplings is revealed in the abstract simulator of
ML
-
DEVS
.
Improving Write Performance by Controlling Target Resistance Distributions in MLC PRAM
Authors: Kim Youngsik , Yoo Sungjoo , Lee Sunggu
Published: February 2016

Multi-level cell (MLC) phase change RAM (PRAM) is expected to offer lower cost main memory than DRAM. However, poor write performance is one of the most critical problems for practical applications of MLC PRAM. In this article, we present two schemes to improve write performance by controlling the target resistance distribution of MLC PRAM cells. First, we propose multiple RESET/SET operations that relax the target resistance bands of intermediate logic levels with additional RESET/SET operations, which reduces the program time of intermediate logic levels, thereby improving write performance. Second, we propose a two-step write scheme consisting of lightweight write and idle-time completion write that exploits the fact that hot dirty data tend to be overwritten in a short time period and the MLC PRAM often has long idle times. Experimental results show that the multiple RESET/SET and two-step write schemes result in an average IPC improvement of 15.7% and 10.4%, respectively, on a hybrid DRAM/PRAM main memory subsystem. Furthermore, their integrated solution results in an average IPC improvement of 23.2% (up to 46.4%).
A New Unicast-Based Multicast Scheme for Network-on-Chip Router and Interconnect Testing
Authors: Xiang Dong , Shen Kele
Published: February 2016

3D technology for networks-on-chip (NOCs) becomes attractive. It is important to present an effective scheme for 3D stacked NOC router and interconnect testing. A new approach to testing of NOC routers is proposed by classifying the routers. Routers with the same number of input/output ports fall into the same class. Routers of the same class are identical if their tests are the same. A test packet is delivered to all the identical routers by a simple unicast-based multicast scheme. It is found that the depth of the consumption buffer at each router has great impact on the test delivery time because test application and test delivery for router testing cannot be handled concurrently. Test delivery must set a router to operational mode. A mathematical model is presented to evaluate the impact of consumption buffer depth on the test delivery time. A new and simple test application scheme is proposed for interconnect testing. Some interesting extensions are presented for further test time reduction and thermal considerations. Sufficient experimental results are presented by comparison with one previous method. The proposed method works for single stuck-at, transition, even small delay faults at routers, and single bridging faults at physical, consumption and injection channels.