bluuebunny/crossref_metadata_2025 huggingface dataset:
Interface layer of a two-component Bose–Einstein condensate
Authors: Aftalion Amandine , Sourdis Christos
Published: June 2016

This paper deals with the study of the behavior of the wave functions of a two-component Bose–Einstein condensate near the interface, in the case of strong segregation. This yields a system of two coupled ordinary differential equations for which we want to have estimates on the asymptotic behavior, as the strength of the coupling tends to infinity. As in phase separation models, the leading order profile is a hyperbolic tangent. We construct an approximate solution and use the properties of the associated linearized operator to perturb it into a genuine solution for which we have an asymptotic expansion. We prove that the constructed heteroclinic solutions are linearly nondegenerate, in the natural sense, and that there is a spectral gap, independent of the large interaction parameter, between the zero eigenvalue (due to translations) at the bottom of the spectrum and the rest of the spectrum. Moreover, we prove a uniqueness result which implies that, in fact, the constructed heteroclinic is the unique minimizer (modulo translations) of the associated energy, for which we provide an expansion.
Motion of slightly compressible fluids in a bounded domain, II
Authors: Disconzi Marcelo M. , Ebin David G.
Published: June 2016

We study the problem of inviscid slightly compressible fluids in a bounded domain. We find a unique solution to the initial-boundary value problem and show that it is near the analogous solution for an incompressible fluid provided the initial conditions for the two problems are close. In particular, the divergence of the initial velocity of the compressible flow at time zero is assumed to be small. Furthermore, we find that solutions to the compressible motion problem in Lagrangian coordinates depend differentiably on their initial data, an unexpected result for this type of nonlinear equations.
Zero Thermal Noise in Resistors at Zero Temperature
Authors: Kish Laszlo B. , Niklasson Gunnar A. , Granqvist Claes-Göran
Published: June 2016

The bandwidth of transistors in logic devices approaches the quantum limit, where Johnson noise and associated error rates are supposed to be strongly enhanced. However, the related theory — asserting a temperature-independent quantum zero-point (ZP) contribution to Johnson noise, which dominates the quantum regime — is controversial and resolution of the controversy is essential to determine the real error rate and fundamental energy dissipation limits of logic gates in the quantum limit. The Callen–Welton formula (fluctuation–dissipation theorem) of voltage and current noise for a resistance is the sum of Nyquist’s classical Johnson noise equation and a quantum ZP term with a power density spectrum proportional to frequency and independent of temperature. The classical Johnson–Nyquist formula vanishes at the approach of zero temperature, but the quantum ZP term still predicts non-zero noise voltage and current. Here, we show that this noise cannot be reconciled with the Fermi–Dirac distribution, which defines the thermodynamics of electrons according to quantum-statistical physics. Consequently, Johnson noise must be nil at zero temperature, and non-zero noise found for certain experimental arrangements may be a measurement artifact, such as the one mentioned in Kleen’s uncertainty relation argument.
Noise Monitoring and Mapping for Some Pre-selected Locations of New Delhi, India
Authors: Akhtar Nasim , Ahmad Kafeel , Alam Pervez
Published: June 2016

Road traffic is one of the major sources of noise pollution in urban areas. Noise measurements and sound observation surveys, alone or in relationship, can be helpful in understanding the complex problem of noise pollution in urban areas. The main aim of this paper is monitoring and mapping for some pre-selected locations of New Delhi, India. The [Formula: see text], noise climate, and noise pollution levels were calculated, this was further represented in the form of cartographic maps for easy understanding. Result of noise monitoring shows that the values of [Formula: see text] at Ashram ranges from 67.4 dB (A) to 82.3 dB (A) which is maximum of all pre-selected locations. It was found that the noise levels at all pre-selected location has been very high and above the permissible limits. Noise map shows that Ashram is the most affected area, most of the pre-selected locations are severally affected and the areas are in constant exposure of noise up to 80 dB vertically as well as horizontally.
Two questions on domains in which locally principal ideals are invertible
Authors: Xing Shiqi , Wang Fanggui
Published: June 2016

An LPI domain is a domain in which every locally principal ideal is invertible. In this paper, we give a negative answer to a question of Anderson–Zafrullah. We show that if [Formula: see text] is an LPI domain and [Formula: see text] is a multiplicatively closed set, then [Formula: see text] is not necessarily an LPI domain. Concerning a question of Bazzoni, we give a characterization of finite character for a finitely stable LPI-domain. We show that if [Formula: see text] is a finitely stable LPI-domain, then every nonzero nonunit element of [Formula: see text] is contained in only finitely many maximal ideals which are in [Formula: see text], and [Formula: see text] is of finite character if and only if each nonzero nonunit element is contained in only finitely many nonstable maximal ideals. A maximal ideal [Formula: see text] is in [Formula: see text] provided there is a finitely generated ideal [Formula: see text] such that [Formula: see text] is the only maximal ideal containing [Formula: see text].
Involutive groups, unique 2-divisibility, and related gyrogroup structures
Authors: Suksumran Teerapong
Published: June 2016

In this paper, we establish a strong connection between groups and gyrogroups, which provides the machinery for studying gyrogroups via group theory. Specifically, we prove that there is a correspondence between the class of gyrogroups and a class of triples with components being groups and twisted subgroups. This in particular provides a construction of a gyrogroup from a group with an automorphism of order two that satisfies the uniquely 2-divisible property. We then present various examples of such groups, including the general linear groups over [Formula: see text] and [Formula: see text], the Clifford group of a Clifford algebra, the Heisenberg group on a module, and the group of units in a unital C[Formula: see text]-algebra. As a consequence, we derive polar decompositions for the groups mentioned previously.
NUMERICAL ANALYSIS OF TEMPERATURE, SCREWING MOMENT AND THRUST FORCE USING FINITE ELEMENT METHOD IN BONE SCREWING PROCESS
Authors: ERDEM MEHMET , GOK KADIR , GOKCE BARIS , GOK ARIF
Published: June 2016

In this study, the bone screwing process carried out with M3.5 cortex screw for stabilization after reduction of femur shaft fracture was investigated both experimentally and numerically. The numerical analyses were performed based on the finite element method using Deform-3D software. The friction, material model, the loading and boundary conditions were exactly identified for finite element analyses. An analytic model and software were developed, which calculate the process parameters such as screwing power and thrust power, heat transfer coefficients in order to determine the temperature distributions occurring in the screw and bone material (sawbones) during screwing process. As a result, the screwing moment and thrust force values decrease with increase of spindle speed. On the contrary, temperature values of screw and sawbones increase with increase of spindle speed. A good consistency between the results obtained from both experimental and numerical simulations was found during the bone screwing process.
DYNAMIC ANALYSIS OF HEALTHY AND EDGE-TO-EDGE REPAIRED MITRAL VALVE BEHAVIOR SUBJECTED TO HIGH G ACCELERATIONS
Authors: SHARIFIKIA DANIAL , ASGARI MASOUD
Published: June 2016

As the mitral leaflets have the greatest area among heart valves and bear the highest pressure load during systole, high G accelerations may result in mitral valve dysfunctions and it might affect the cardiovascular system drastically. In this study, dynamic behavior of healthy and repaired human mitral valves have been numerically simulated during the Early Systolic Phase and the Rapid Filling Phase in a cardiac cycle in high G accelerated environments. The aim of this study is to investigate the effects of accelerations on the stress and strain patterns and the configuration of human mitral valve. The geometrical model of the mitral valve has been developed based on in vivo and ex vivo anatomical measurements and the anisotropic nonlinear behavior of mitral leaflets has been modeled by a discrete constitutive approach. Mitral valve behavior has been simulated using an explicit dynamic finite element method to take into account inertial effects and dynamic responses. Analysis results reveal beside different stress–strain patterns generated on mitral leaflets, abnormal deformed configurations result from accelerations which can affect the circulation and the cardiovascular system. It is observed that situations similar to mitral diseases could rise from high G accelerated environments even though the valve maintains its normal physiological structure.
Designing L-serine targeted molecularly imprinted polymer via theoretical investigation
Authors: Singh Ambareesh Kumar , Singh Meenakshi
Published: June 2016

Molecular imprinting is one of few general, nonbiological methods for creating molecular receptors, but the progress in molecular imprinting calls for the predictive tools capable of understanding molecular level complexities of these processes. Thus, computational chemistry which predicts the suitability of functional monomer in designing the sensor for a particular analyte was attempted to design an amino acid (L-serine) sensor based on the molecular imprinting approach using density functional theory (DFT). Here, the computations were carried out to check the feasibility of best suited monomers for imprinting an amino acid (L-serine) in water and allied solvents.

DFT method was utilized at B3LYP/6-31[Formula: see text]G(d,p) level to optimize template, monomers and template-monomer complexes and basis set superposition error (BSSE) was corrected by means of the counterpoise (CP) method for complexes in gas phase. All monomers can be utilized for imprinting. 2-vinyl pyridine and acrylamide were found to be good for imprinting serine in water but toluene was found to be good porogen for imprinting serine with functional monomer acrylamide. This study will aid in designing a water-compatible MIP sensor for serine molecules, which could be a biomarker for certain neurological disorders.
Quantum chemical and spectroscopic investigations of 4-Hydroxy-7-methyl-1,8-naphthyridine-3-carboxylic acid
Authors: Bhat Sheeraz Ahmad , Ahmad Shabbir
Published: June 2016

The FTIR (4000–400[Formula: see text]cm[Formula: see text]) and the FT-Raman spectra (4000–50[Formula: see text]cm[Formula: see text]) of 4-Hydroxy-7-methyl-1,8-naphthyridine-3-carboxylic acid are recorded and investigated. The spectra are interpreted using anharmonic frequency computations by VPT2, VSCF and PT2-VSCF methods within DFT/6-311G(d,p) framework. The root mean square (RMS) values indicate that VSCF computed frequencies are in close agreement with the observed frequencies. The combination and overtone bands are also identified in the FTIR spectrum. The intermolecular O-H[Formula: see text]O hydrogen bonding interactions are discussed in the dimer structure of the molecule. The magnitudes of the coupling between pair of modes are also computed. The electronic spectra in water and ethanol solvents are analyzed using TD-B3LYP/6-311[Formula: see text]G(d,p) level of theory. Molecular electrostatic potential (MEP) and HOMO-LUMO analysis are also performed.
Development of Universal Robot Gripper Using MRα Fluid
Authors: Nishida Takeshi , Okatani Yuki , Tadakuma Kenjiro
Published: June 2016

In this paper, we developed a universal robot gripper using an electromagnet and a novel reforming magnetorheological (MR) fluid. First, we added nonmagnetic particles to an MR fluid to develop a novel reforming MR fluid called MR[Formula: see text] fluid; this fluid resolved several issues faced with MR fluids. The developed fluid’s specific gravity is one-half and solidification hardness is two times that of MR fluid. The characteristics of the MR[Formula: see text] fluid and an application that can control solidification under a magnetic field are described. Next, the developed gripper, which consists of an electromagnet and an elastic membrane that encloses the MR[Formula: see text] fluid, is described. Further, several experimental results of the features and capabilities of the gripper are presented.
Challenges for Instilling Entrepreneurial Mindset in Scientists and Engineers: What Works in European Universities?
Authors: Secundo Giustina , Ndou Valentina , Del Vecchio Pasquale
Published: June 2016

The development of entrepreneurial mindsets in graduated students with science and engineering backgrounds represents an emerging priority for the higher education systems. However, this dimension is still in infancy, especially in Europe. Aimed to contribute at this debate, the study provides evidences on how European universities are approaching this goal. Based on a cross-case analysis of 22 post-graduated programs, the study explores the emerging trends and the “invariance” traits adopted to develop high qualified human capital with an entrepreneurial mindset. Implications for theory and practice include the most pressing challenges for universities involved in their transitions towards an entrepreneurial configuration.
The geometrical and algebraic interpretations of Euler–Rodrigues formula in Minkowski 3-space
Authors: Kahvecí Derya , Yayli Yusuf , Gök Ísmaíl
Published: June 2016

The aim of this paper is to give the geometrical and algebraic interpretations of Euler–Rodrigues formula in Minkowski 3-space. First, for the given non-lightlike axis of a unit length in [Formula: see text] and angle, the spatial displacement is represented by a [Formula: see text] semi-orthogonal rotation matrix using orthogonal projection. Second, we obtain the classifications of Euler–Rodrigues formula in terms of semi-skew-symmetric matrix corresponds to spacelike, timelike or lightlike axis and rotation angle with the help of exponential map. Finally, an alternative method is given to find rotation axis and the Euler–Rodrigues formula is expressed via split quaternions in Minkowski 3-space.
Drug Delivery Based on Swarm Microrobots
Authors: Banharnsakun Anan , Achalakul Tiranee , Batra Romesh C
Published: June 2016

Advances in the development of technology have led to microrobots applications in medical fields. Drug delivery is one of these applications in which microrobots deliver a pharmaceutical compound to targeted cells. Chemotherapy and its side effects can then be minimized by this method. Two major constraints, however, must be considered: the robot’s onboard energy supply and the time needed for drug delivery. Furthermore, a microrobot must avoid biological restricted areas which we treat as obstacles in the path. The main objectives of this work were to find optimal paths to targeted cells and avoid collision with obstacles in the paths under a dynamic environment. In this study, we controlled motion of microrobots based on the concept of swarm intelligence. Artificial Bee Colony (ABC), the Best-so-far ABC, and the Particle Swarm Optimization (PSO) methods were employed to implement the collision detection and the boundary distance detection modules. Forces that drove or resisted blood flow as well as pressure in blood vessels were considered to approximate the effects of the environment on the microrobots. Numerical experiments were conducted using various obstacle environments. The results confirm that the proposed approaches were successful in avoiding obstacles and optimizing the energy consumption used to reach the target.
Implementation of Fuzzy Time Series in Forecasting of the Non-Stationary Data
Authors: Efendi Riswan , Deris Mustafa Mat , Ismail Zuhaimy
Published: June 2016

To forecast the non-stationary data is quite difficult when compared with the stationary data time series. Because their variances are not constant and not stable like the second data type. This paper presents the implementation of fuzzy time series (FTS) into the non-stationary time series data forecasting, such as, the electricity load demand, the exchange rates, the enrollment university and others. These data forecasts are derived by implementing of the weightage and linguistic out-sample methods. The result shows that the FTS can be applied in improving the accuracy and efficiency of these non-stationary data forecasting opportunities.
Multiscale Modeling of Novel Carbon Nanotube/Copper-Composite Material Used in Microelectronics
Authors: Awad Ibrahim , Ladani Leila
Published: June 2016

Current carrying capacity is one of the elements that hinders further miniaturization of Copper (Cu) interconnects. Therefore, there is a need to propose new materials with higher ampacity (current carrying capacity) that have the potential to replace Cu. Experimental observations have shown that Carbon Nanotube (CNT)/Cu-composite material has a hundredfold ampacity of Cu, which makes it a good candidate to replace Cu. However, sufficient information about the mechanical behavior of the novel CNT/Cu-composite is not available. In the current paper, the CNT/Cu-composite is utilized to construct Through Silicon Via (TSV). The mechanical behavior, specifically the fatigue life, of the CNT/Cu–TSV is evaluated by applying a multiscale modeling approach. Molecular Dynamics (MD) simulations are conducted to evaluate the tensile strength and the coefficient of thermal expansion of CNTs. MD simulation is also used to determine the interface behavior between CNTs and Cu. MD simulation results are integrated into Finite Element analysis at the micro-level to estimate the fatigue life of the CNT/Cu–TSV. A comparison is made with base material; Cu. CNTs addition has redistributed the plastic deformation in Cu to occur at two different locations (Si/Cu interface and Cu/CNT interface) instead of only one location (Si/Cu interface) in the case of Cu-only-TSV. Thus, the maximum equivalent plastic strain has been alleviated in the CNT/Cu–TSV. Accordingly, CNT/Cu–TSV has shown a threefold increase in the fatigue life. This is a solid indication of the improvement in the fatigue life that is attributed to the addition of CNTs.
Diagnostic of the Bimodal Distribution of InAs/GaAs Quantum Dots by Means of a Simple Nondestructive Method Based on the Photoelectrical Spectroscopy
Authors: Volkova N. S. , Gorshkov A. P. , Istomin L. A. , Zdoroveyshchev A. V. , Levichev S.
Published: June 2016

Photoelectric spectra of heterostructures containing InAs quantum dots (QDs) produced in different technological regimes were studied. A simple nondestructive method to reveal a bimodality of the QDs’ size distribution was described. The method based on the analysis of the shape of InAs/GaAs QDs’ photoelectric spectra and their temperature dependencies. The quantitative analysis of the temperature dependencies of the photoelectrical spectra was performed. All possible emission processes occurring from quantum confined levels to the semiconductor matrix were considered at the simulation. The surface concentration of the QDs was estimated.
Tunable Optical Properties of Ag–TiO2 Nanorod Composites Based on Interparticle Plasmon Coupling
Authors: Zhang Yong , Liu Fa-Min
Published: June 2016

The metal–semiconductor composites with unique optical properties are highly desirable. Here we report that Ag–TiO2 nanorod composites with two distinctive absorption peaks exhibit tunable plasmon coupling behaviors. The intensity of the long-wave absorption could be enhanced by modifying the geometry of TiO2 particles, while such absorption is due to the plasmon coupling between the Ag particles. The long-wave absorption bands can be tuned by varying the reaction time and changing the amount of silver acetate. Furthermore, the Ag–TiO2 composites were also prepared by photochemical reduction method which confirmed the previous properties. These results may help to design metal–semiconductor systems with desirable optical properties.
Intercalated Polyaniline/Halloysite Nanocomposites by a Solvent-Free Mechanochemical Method
Authors: Zheng Hao , Cheng Huijun , Zhou Lu , Ye Ying , Chen Jianfang
Published: June 2016

This article has been retracted. A statement of retraction is published in Nano Volume 11, Issue 12 (2016).
Global dynamics of a viral infection model with full logistic terms and antivirus treatments
Authors: Song Lijuan , Ma Cui , Li Qiang , Fan Aijun , Wang Kaifa
Published: June 2016

In this paper, mathematical analysis of the global dynamics of a viral infection model in vivo is carried out. Though the model is originally to study hepatitis C virus (HCV) dynamics in patients with high baseline viral loads or advanced liver disease, similar models still hold significance for other viral infection, such as hepatitis B virus (HBV) or human immunodeficiency virus (HIV) infection. By means of Volterra-type Lyapunov functions, we know that the basic reproduction number [Formula: see text] is a sharp threshold para-meter for the outcomes of viral infections. If [Formula: see text], the virus-free equilibrium is globally asymptotically stable. If [Formula: see text], the system is uniformly persistent, the unique endemic equilibrium appears and is globally asymptotically stable under a sufficient condition. Other than that, for the global stability of the unique endemic equilibrium, another sufficient condition is obtained by Li–Muldowney global-stability criterion. Using numerical simulation techniques, we further find that sustained oscillations can exist and different maximum de novo hepatocyte influx rate can induce different global dynamics along with the change of overall drug effectiveness. Finally, some biological implications of our findings are given.
Faber polynomial coefficient estimates for a class of analytic bi-univalent functions involving a certain differential operator
Authors: Sharma Poonam
Published: June 2016

In this paper, we define a sub-class of analytic bi-univalent functions associated with a certain differential operator [Formula: see text]. Bounds for the general Taylor–Maclaurin coefficients [Formula: see text] for the functions in this class are obtained. Estimates for the coefficient [Formula: see text] and the estimate for the functional [Formula: see text] for any real [Formula: see text], are also found. Results for the specific values of the parameters [Formula: see text], are also given mentioning some of the results obtained earlier.
A modified optimal algorithm for 2-maxian location problems on cactus graphs
Authors: Modabber L. , Alizadeh B. , Baroughi F.
Published: June 2016

This paper considers the [Formula: see text]-maxian location problem on a cactus graph [Formula: see text] in which the aim is to find two points on [Formula: see text] for establishing obnoxious facilities such that the sum of weighted distances from all vertices (existing clients) to the farthest facility is maximized. We develop a modified algorithm for obtaining an optimal solution of the problem under investigation. The proposed algorithm is based on the generic solution idea by Kang et al., while it is straightforward and takes lower computational operations.
Impact of crystal structure singularity on transport and electrochemical properties of Lix(LiyFezV1−y−z)O2 — electrode material for lithium batteries
Authors: Gędziorowski Bartłomiej , Tobola Janusz , Braun Artur , Molenda Janina
Published: June 2016

Lithium vanadium oxide (LiVO2) and its substituted derivatives are a distinctive group of materials that may act both, as cathode and anode materials for Li-ion batteries. This paper presents influence of crystal structure singularity of Li(LiyFezV[Formula: see text])O2 ([Formula: see text], 0.03, 0.07, [Formula: see text], 0.05, 0.1) on transport and electrochemical properties of the compounds.
Enhancement of electrochemical performance of LiFePO4nanoparticles by direct nanocoating with conductive carbon layers
Authors: Świder Joanna , Molenda Marcin , Kulka Andrzej , Molenda Janina
Published: June 2016

The results of simple and environmental-friendly method of the carbon nanocoatings on low-conductive cathode material have been shown in this work. The carbon nanocoatings were prepared during wet impregnation process of precursor derived from hydrophilic polymer based on poly([Formula: see text]-vinylformamide) modified by pyromellitic acid. The crystal structures and morphology of all composites were characterized by X-ray powder diffraction (XRD), low temperature nitrogen adsorption/desorption measurements (N2-BET) and transmission electronic microscopy (TEM). The electrical properties of the obtained composites were examined by EC studies. The electrochemical performance was carried out in galvanostatic mode with stable charge–discharge current and performed in Li/Li[Formula: see text]/(CCL/LiFePO[Formula: see text] type cells. The process of formation CCL/LiFePO4nanocomposite significantly enhances the electrical conductivity of the material and improves its capacity retention and electrochemical performance.
Positive magnetoresistance of La0.7Sr0.3MnO3/C composites
Authors: Kabirov Yu. V. , Gavrilyachenko V. G. , Bogatin A. S.
Published: June 2016

The perovskite manganite La[Formula: see text]Sr[Formula: see text]MnO3 compound is used as a component in ceramic ([Formula: see text](La[Formula: see text]Sr[Formula: see text]MnO[Formula: see text]-xC composites at x = 0.15–0.85. It is found that every studied specimen is characterized by the linear dependence of the positive magnetoresistance (PMR) on the magnetic field strength at room temperature. The 0.6(La[Formula: see text]Sr[Formula: see text]MnO[Formula: see text]-0.4C composite has the largest magnetoresistance value (15%) at room temperature and intensity of magnetic field [Formula: see text][Formula: see text]kOe. A possible mechanism for the PMR of ([Formula: see text](La[Formula: see text]Sr[Formula: see text]MnO[Formula: see text]-xC composites is discussed.
A study on the injective coloring parameters of certain graphs
Authors: Sudev N. K. , Chithra K. P. , Satheesh S. , Kok Johan
Published: June 2016

Coloring the vertices of a graph [Formula: see text] according to certain conditions can be considered as a random experiment and a discrete random variable (r.v.) [Formula: see text] can be defined as the number of vertices having a particular color in the proper coloring of [Formula: see text] and a probability mass function for this random variable can be defined accordingly. In this paper, we extend the concepts of mean and variance to a modified injective graph coloring and determine the values of these parameters for a number of standard graphs.
The Development Tendency of the Real Estate Industry under China’s Economic “New Normal”
Authors: WANG Yeqiang
Published: June 2016

Under the economic “new normal”, the real estate industry experiences a transition from seller’s market to buyer’s market; the construction of indemnificatory housing becomes the main approach of macroeconomic control; the source of real estate funds turns from single credit to diverse financing; the mechanism of macro control gradually becomes market-oriented and the development mode gradually turns pluralistic. At the same time, the real estate industry is facing challenges from local debt crisis, tax reformation, online businesses and transformation of production mode. However, this paper proposes that there’s no fundamental alternation in the basic aspects of macroeconomy that supports China’s real estate development, and the “new normal” of China’s real estate market should be led by reformation and innovation.
Entrepreneurship Research in Asia: What We Know and Where We Move in the Future
Authors: Bruton Garry D. , Chen Juanyi
Published: June 2016

Examining 139 articles since 2000 published in leading management journals, we highlight that to date the field of entrepreneurship remains critically underrepresented among leading journals. The articles that have been published tend to take concepts from the West, replicate them in a single nation in Asia, and then discuss why the results were different from the West. There remains a rich range of topics that need to be examined in Asia. The development of this future research should focus not only on boundary conditions to the research from the West but scholars should also seek to begin to develop unique streams of insight that begin to utilize existing theory to develop unique Asian insights to entrepreneurship.
Spatial-Proximity Optimization for Rapid Task Group Deployment
Authors: Shen Chih-Ya , Yang De-Nian , Lee Wang-Chien , Chen Ming-Syan
Published: June 2016

Spatial proximity is one of the most important factors for the quick deployment of the task groups in various time-sensitive missions. This article proposes a new spatial query,
Spatio-Social Team Query (SSTQ)
, that forms a strong task group by considering (1) the group’s spatial distance (i.e., transportation time), (2) skills of the candidate group members, and (3) social rapport among the candidates. Efficient processing of SSTQ is very challenging, because the aforementioned spatial, skill, and social factors need to be carefully examined. In this article, therefore, we first formulate two subproblems of SSTQ, namely
Hop-Constrained Team Problem (HCTP)
and
Connection-Oriented Team Query (COTQ)
. HCTP is a decision problem that considers only social and skill dimensions. We prove that HCTP is NP-Complete. Moreover, based on the hardness of HCTP, we prove that SSTQ is NP-Hard and
inapproximable within any factor
. On the other hand, COTQ is a special case of SSTQ that relaxes the social constraint. We prove that COTQ is NP-Hard and propose an approximation algorithm for COTQ, namely
COTprox
. Furthermore, based on the observations on COTprox, we devise an approximation algorithm,
SSTprox
, with a guaranteed error bound for SSTQ. Finally, to efficiently obtain the optimal solution to SSTQ for small instances, we design two efficient algorithms,
SpatialFirst
and
SkillFirst
, with different scenarios in mind. These two algorithms incorporate various effective ordering and pruning techniques to reduce the search space for answering SSTQ. Experimental results on real datasets indicate that the proposed algorithms can efficiently answer SSTQ under various parameter settings.
Matslise 2.0
Authors: Ledoux Veerle , Van Daele Marnix
Published: June 2016

The
Matslise
2.0 software package is a thorough revision of the successful Matlab package
Matslise
of 2005. The package can be used to compute the eigenvalues and eigenfunctions of regular and some important classes of singular self-adjoint Sturm-Liouville boundary value problems. The code uses new or improved algorithms, offers some new features, and has an updated graphical user interface.
Inferring Dynamic Diffusion Networks in Online Media
Authors: Tahani Maryam , Hemmatyar Ali M. A. , Rabiee Hamid R. , Ramezani Maryam
Published: June 2016

Online media play an important role in information societies by providing a convenient infrastructure for different processes. Information diffusion that is a fundamental process taking place on social and information networks has been investigated in many studies. Research on information diffusion in these networks faces two main challenges: (1) In most cases, diffusion takes place on an underlying network, which is latent and its structure is unknown. (2) This latent network is not fixed and changes over time. In this article, we investigate the diffusion network extraction (DNE) problem when the underlying network is dynamic and latent. We model the diffusion behavior (existence probability) of each edge as a stochastic process and utilize the Hidden Markov Model (HMM) to discover the most probable diffusion links according to the current observation of the diffusion process, which is the infection time of nodes and the past diffusion behavior of links. We evaluate the performance of our Dynamic Diffusion Network Extraction (DDNE) method, on both synthetic and real datasets. Experimental results show that the performance of the proposed method is independent of the cascade transmission model and outperforms the state of art method in terms of F-measure.
Exploiting Hierarchical Locality in Deep Parallel Architectures
Authors: Anbar Ahmad , Serres Olivier , Kayraklioglu Engin , Badawy Abdel-Hameed A. , El-Ghazawi Tarek
Published: June 2016

Parallel computers are becoming deeply hierarchical. Locality-aware programming models allow programmers to control locality at one level through establishing affinity between data and executing activities. This, however, does not enable locality exploitation at other levels. Therefore, we must conceive an efficient abstraction of hierarchical locality and develop techniques to exploit it. Techniques applied directly by programmers, beyond the first level, burden the programmer and hinder productivity. In this article, we propose the Parallel Hierarchical Locality Abstraction Model for Execution (PHLAME). PHLAME is an execution model to abstract and exploit machine hierarchical properties through locality-aware programming and a runtime that takes into account machine characteristics, as well as a data sharing and communication profile of the underlying application. This article presents and experiments with concepts and techniques that can drive such runtime system in support of PHLAME. Our experiments show that our techniques scale up and achieve performance gains of up to 88%.
MInGLE
Authors: González-álvarez Cecilia , Sartor Jennifer B. , Álvarez Carlos , Jiménez-González Daniel , Eeckhout Lieven
Published: June 2016

The end of Dennard scaling leads to new research directions that try to cope with the utilization wall in modern chips, such as the design of specialized architectures. Processor customization utilizes transistors more efficiently, optimizing not only for performance but also for power. However, hardware specialization for each application is costly and impractical due to time-to-market constraints. Domain-specific specialization is an alternative that can increase hardware reutilization across applications that share similar computations. This article explores the specialization of low-power processors with custom instructions (CIs) that run on a specialized functional unit. We are the first, to our knowledge, to design CIs for an application domain
and
across basic blocks, selecting CIs that maximize both performance and energy efficiency improvements.

We present the Merged Instructions Generator for Large Efficiency (MInGLE), an automated framework that identifies and selects CIs. Our framework analyzes large sequences of code (across basic blocks) to maximize acceleration potential while also performing partial matching across applications to optimize for reuse of the specialized hardware. To do this, we convert the code into a new canonical representation, the Merging Diagram, which represents the code’s functionality instead of its structure. This is key to being able to find similarities across such large code sequences from different applications with different coding styles. Groups of potential CIs are clustered depending on their similarity score to effectively reduce the search space. Additionally, we create new CIs that cover not only whole-body loops but also fragments of the code to optimize hardware reutilization further. For a set of 11 applications from the media domain, our framework generates CIs that significantly improve the energy-delay product (EDP) and performance speedup. CIs with the highest utilization opportunities achieve an average EDP improvement of 3.8 × compared to a baseline processor modeled after an Intel Atom. We demonstrate that we can efficiently accelerate a domain with partially matched CIs, and that their design time, from identification to selection, stays within tractable bounds.
COBAYN
Authors: Ashouri Amir Hossein , Mariani Giovanni , Palermo Gianluca , Park Eunjung , Cavazos John , Silvano Cristina
Published: June 2016

The variety of today’s architectures forces programmers to spend a great deal of time porting and tuning application codes across different platforms. Compilers themselves need additional tuning, which has considerable complexity as the standard optimization levels, usually designed for the average case and the specific target architecture, often fail to bring the best results.

This article proposes
COBAYN
: Compiler autotuning framework using BAYesian Networks, an approach for a compiler autotuning methodology using machine learning to speed up application performance and to reduce the cost of the compiler optimization phases. The proposed framework is based on the application characterization done dynamically by using independent microarchitecture features and Bayesian networks. The article also presents an evaluation based on using static analysis and hybrid feature collection approaches. In addition, the article compares Bayesian networks with respect to several state-of-the-art machine-learning models.

Experiments were carried out on an ARM embedded platform and GCC compiler by considering two benchmark suites with 39 applications. The set of compiler configurations, selected by the model (less than 7% of the search space), demonstrated an application performance speedup of up to 4.6 × on Polybench (1.85 × on average) and 3.1 × on cBench (1.54 × on average) with respect to standard optimization levels. Moreover, the comparison of the proposed technique with (i) random iterative compilation, (ii) machine learning--based iterative compilation, and (iii) noniterative predictive modeling techniques shows, on average, 1.2 × , 1.37 × , and 1.48 × speedup, respectively. Finally, the proposed method demonstrates 4 × and 3 × speedup, respectively, on cBench and Polybench in terms of exploration efficiency given the same quality of the solutions generated by the random iterative compilation model.
Breaking the cycle of Macondo: design and decolonial futures
Authors: de O. Martins Luiza Prado , de Oliveira Pedro J. S. Vieira
Published: June 2016

How can the ideas of timelessness and anachronism contribute to the decolonization of design practices in Latin America?
A tale of two cities, real and imagined
Authors: Bhatia Rahul
Published: June 2016

How an election promise to develop India's smart cities became an urban concern.
Decolonising HCI and interaction design discourse: some considerations in planning AfriCHI
Authors: Bidwell Nicola J.
Published: June 2016

Bringing African theorists into the construction of African identity in HCI.
A brief introduction to decolonial computing
Authors: Ali Syed Mustafa
Published: June 2016

Does computing need to be decolonized, and if so, how should such decolonization be effected? This short essay introduces a recent proposal at the fringes of computing, which attempts to engage these and other related questions.
Is your research reproducible?
Authors: Hosny Abdelrahman
Published: June 2016

The
XRDS
blog highlights a range of topics from conference coverage, to security and privacy, to CS theory. Selected blog posts, edited for print, are featured in every issue. Please visit xrds.acm.org/blog to read each post in its entirety. If you are interested in joining as a student blogger, please contact us.
Why you need Allies as a Ph.D.
Authors: Hunsucker Andrew J.
Published: June 2016

Good research requires strong connections.
Meeting point: the computer lab
Authors: Schacht Johanna
Published: June 2016

Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
Archaeological Evidence of Epidemics Can Inform Future Epidemics
Authors: DeWitte Sharon N.
Published: June 2016

The recent Ebola epidemic provides a dramatic example of the devastation and fear generated by epidemics, particularly those caused by new emerging or reemerging diseases. A focus on the control and prevention of diseases in living populations dominates most epidemic disease research. However, research on epidemics in the past provides a temporal depth to our understanding of the context and consequences of diseases and is crucial for predicting how diseases might shape human biology and demography in the future. This article reviews recent research on historic epidemics of plague and tuberculosis, both of which have affected human populations for millennia. Research on these diseases demonstrates the range (and differential availability) of various lines of evidence (e.g., burial context, diagnostic skeletal lesions, molecular data) that inform about past disease in general. I highlight how research on past epidemics may be informative in ways that benefit living populations.
Urban Space and Exclusion in Asia
Authors: Harms Erik
Published: June 2016

The much-vaunted growth of cities across Asia has been accompanied by new forms of urban exclusion. This article reviews recent research into urban space and exclusion in Asia, focusing on anthropology as well as on key works in cognate fields such as geography, political science, sociology, and urban studies. The review of the literature suggests that spatial exclusions in Asian cities are perpetuated by numerous different modes, some overt and intentional, others tacit and unintentional, and that inclusion and exclusion are often entangled with each other. Six representative modes of exclusion are outlined: paperwork, money, violence, environment, space, and civility. Essential scholarship about each mode of exclusion is introduced, and it is suggested that the best scholarly work on urban exclusion investigates the overlaps and intersections of modes such as these.
Signaling Networks Determining Life Span
Authors: Riera Celine E. , Merkwirth Carsten , De Magalhaes Filho C. Daniel , Dillin Andrew
Published: June 2016

The health of an organism is orchestrated by a multitude of molecular and biochemical networks responsible for ensuring homeostasis within cells and tissues. However, upon aging, a progressive failure in the maintenance of this homeostatic balance occurs in response to a variety of endogenous and environmental stresses, allowing the accumulation of damage, the physiological decline of individual tissues, and susceptibility to diseases. What are the molecular and cellular signaling events that control the aging process and how can this knowledge help design therapeutic strategies to combat age-associated diseases? Here we provide a comprehensive overview of the evolutionarily conserved biological processes that alter the rate of aging and discuss their link to disease prevention and the extension of healthy life span.
Insights into Cotranslational Nascent Protein Behavior from Computer Simulations
Authors: Trovato Fabio , O'Brien Edward P.
Published: June 2016

Regulation of protein stability and function in vivo begins during protein synthesis, when the ribosome translates a messenger RNA into a nascent polypeptide. Cotranslational processes involving a nascent protein include folding, binding to other macromolecules, enzymatic modification, and secretion through membranes. Experiments have shown that the rate at which the ribosome adds amino acids to the elongating nascent chain influences the efficiency of these processes, with alterations to these rates possibly contributing to diseases, including some types of cancer. In this review, we discuss recent insights into cotranslational processes gained from molecular simulations, how different computational approaches have been combined to understand cotranslational processes at multiple scales, and the new scenarios illuminated by these simulations. We conclude by suggesting interesting questions that computational approaches in this research area can address over the next few years.
Lymphangiogenesis: Origin, Specification, and Cell Fate Determination
Authors: Escobedo Noelia , Oliver Guillermo
Published: June 2016

The two vascular systems of our body are the blood and the lymphatic vasculature. Our understanding of the genes and molecular mechanisms controlling the development of the lymphatic vasculature network has significantly improved. The availability of novel animal models and better imaging tools led to the identification of lymphatics in tissues and organs previously thought to be devoid of them. Similarly, the classical textbook list of established functional roles of the lymphatic system has been expanded by the addition of novel findings. In this review we provide a historical perspective of some of the important landmarks that opened the doors to researchers working in this field. We also summarize some of the current views about embryonic lymphangiogenesis, particularly about the source(s), commitment, and differentiation of lymphatic endothelial cells.
Neurogenesis and Gliogenesis in Nervous System Plasticity and Repair
Authors: Frisén Jonas
Published: June 2016

The brain constantly changes to store memories and adapt to new conditions. One type of plasticity that has gained increasing interest during the last years is the generation of new cells. The generation of both new neurons and glial cells contributes to neural plasticity and to some neural repair. There are substantial differences between mammalian species with regard to the extent of and mechanisms behind cell exchange in neural plasticity. Both neurogenesis and gliogenesis have several specific features in humans, which may contribute to the unique plasticity of the human brain.
Mechanical Control of Epithelial-to-Mesenchymal Transitions in Development and Cancer
Authors: Przybyla Laralynne , Muncie Jonathon M. , Weaver Valerie M.
Published: June 2016

Mechanical force modulates development, influences tissue homeostasis, and contributes to disease. Forces sculpt tissue-level behaviors and direct cell fate by engaging mechanoreceptors and by altering organization of the cytoskeleton and actomyosin contractility to stimulate mechanotransduction mechanisms that alter transcription. Nevertheless, how force specifically leverages mechanotransduction pathways to control transcriptional regulation of cell fate remains unclear. Here we review recent findings specifically in the context of epithelial-to-mesenchymal transitions that have revealed conserved mechanisms whereby extracellular force, mediated through cell–extracellular matrix and cell-cell junctional complexes, induces transcriptional reprogramming to alter cell and tissue fate. We focus on the interplay between tissue mechanics and the epithelial-to-mesenchymal transitions that occur during embryonic development and cancer malignancy. We describe the adhesion-linked cellular machinery that mediates mechano-transduction and elaborate on how these force-linked networks stimulate key transcriptional programs that induce an epithelial-to-mesenchymal phenotypic transition, thereby providing an overview of how mechanical signals can be translated into a change in cell fate.
Credit Supply Disruptions: From Credit Crunches to Financial Crisis*
Authors: Peek Joe , Rosengren Eric
Published: June 2016

It is useful to reflect on how the financial environment changed between the credit crunch episode of the early 1990s and the recent financial crisis. What did we learn from the earlier crisis, and how did the credit crunch literature help guide policy in the more recent crisis? Two important changes were the consolidation of the banking sector and the dramatic growth in nonbank financial intermediaries, which are much more susceptible than banks to liquidity risks because of a lack of deposit insurance. This article highlights that, although security broker-dealers, money market mutual funds, and issuers of asset-backed securities were not particularly important in the early 1990s, when the bank credit crunch occurred, they grew dramatically to become both major sources of financing and key elements in exacerbating the problems experienced during the recent financial crisis.