bluuebunny/crossref_metadata_2025_split huggingface dataset:
An efficient approach to pose tracking based on odometric error modelling for mobile robots
Authors: Yang Jingdong , Yang Jinghui , Cai Zesu 
Published: April 2014

SUMMARYOdometric error modelling for mobile robots is the basis of pose tracking. Without bounds the odometric accumulative error decreases localisation precision after long-range movement, which is often not capable of being compensated for in real time. Therefore, an efficient approach to odometric error modelling is proposed in regard to different drive type mobile robots. This method presents a hypothesis that the motion path approximates a circular arc. The approximate functional expressions between the control input of odometry and non-systematic error as well as systematic error derived from odometric error propagation law. Further an efficient algorithm of pose tracking is proposed for mobile robots, which is able to compensate for the non-systematic and systematic error in real time. These experiments denote that the odometric error modelling reduces the accumulative error of odometry efficiently and improves the specific localisation process significantly during autonomous navigation.
Quaternion-based EKF-SLAM from relative pose measurements: observability analysis and applications
Authors: Carlone Luca , Macchia Vito , Tibaldi Federico , Bona Basilio 
Published: April 2014

SUMMARYIn this work, we investigate a quaternion-based formulation of 3D Simultaneous Localization and Mapping with Extended Kalman Filter (EKF-SLAM) using relative pose measurements. We introduce a discrete-time derivation that avoids thenormalization problemthat often arises when using unit quaternions in Kalman filter and we study its observability properties. The consistency of the estimation errors with the corresponding covariance matrices is also evaluated. The approach is further tested on real data from theRawseeds datasetand it is applied within a delayed-state EKF architecture for estimating a dense 3D map of an unknown environment. The contribution is motivated by the possibility of abstracting multi-sensorial information in terms of relative pose measurements and for its straightforward extensions to the multi robot case.
Physical-limits-constrained minimum velocity norm coordinating scheme for wheeled mobile redundant manipulators
Authors: Zhang Yunong , Li Weibing , Zhang Zhijun 
Published: April 2014

SUMMARYIn order to resolve the redundancy of a wheeled mobile redundant manipulator comprising a two-wheel-drive mobile platform and a 6-degree-of-freedom manipulator, a physical-limits-constrained (PLC) minimum velocity norm (MVN) coordinating scheme (termed as PLC-MVN-C scheme) is proposed and investigated. Such a scheme can not only coordinate the mobile platform and the manipulator to fulfill the end-effector task and to achieve the desired optimal index (i.e., minimizing the norm of the rotational velocities of the wheels and the joint velocities of the manipulator) but also consider the physical limits of the robot (i.e., the joint-angle limits and joint-velocity limits of the manipulator as well as the rotational velocity limits of the wheels). The scheme is then reformulated as a quadratic program (QP) subject to equality and bound constraints, and is solved by a discrete QP solver, i.e., a numerical algorithm based on piecewise-linear projection equations (PLPE). Simulation results substantiate the efficacy and accuracy of such a PLC-MVN-C scheme and the corresponding discrete PLPE-based QP solver.
A scalable approach for ideation in biologically inspired design
Authors: Vandevenne Dennis , Verhaegen Paul-Armand , Dewulf Simon , Duflou Joost R. 
Published: April 2014

AbstractThis paper presents a bioinspiration approach that is able to scalably leverage the ever-growing body of biological information in natural-language format. The ideation tool AskNature, developed by the Biomimicry 3.8 Institute, is expanded with an algorithm for automated classification of biological strategies into the Biomimicry Taxonomy, a three-level, hierarchical information structure that organizes AskNature's database. In this way, the manual work entailed by the classification of biological strategies can be alleviated. Thus, the bottleneck is removed that currently prevents the integration of large numbers of biological strategies. To demonstrate the feasibility of building a scalable bioideation system, this paper presents tests that classify biological strategies from AskNature's reference database for those Biomimicry Taxonomy classes that currently hold sufficient reference documents.
POLITICS THROUGH POTTERY: A VIEW OF THE PRECLASSIC-CLASSIC TRANSITION FROM BUILDING B, GROUP II, HOLMUL, GUATEMALA
Authors: Callaghan Michael G. 
Published: April 2014

AbstractBuilding B of Group II at Holmul, Guatemala, is well known in Maya archaeology for its unique series of superimposed tombs, some of which contain rare large deposits of ceramic material dating to the Terminal Preclassic period (a.d.1–250). However, the building also contains large deposits of early facet Early Classic (a.d.250–400) material, as well as the remains of a potential title holding elite. This article presents the current ceramic sequence for the Holmul region and a re-evaluation of the ceramic material from all rooms in Building B Group II in light of new discoveries at sites within the Holmul region and the greater Maya lowlands. The result is a new hypothesis about what social processes are manifested through Terminal Preclassic period orange slipped pottery, which suggests that the vessels associated with deposits in Buidling B may represent changes in elite diacritical feasting events during this period. These feasts, and the preparations made for them, may have simultaneously integrated social groups within a polity while also reinforcing differences between them during two turbulent epochs of Maya political history—namely, the late facet of the Terminal Preclassic period (a.d.150–250) and the early facet of the Early Classic period (a.d.250–400).
STRUCTURE 5N2 (“GROUP A”): A RÍO BEC PARADIGMATIC PALACE?
Authors: Michelet Dominique , Nondédéo Philippe , Patrois Julie , Gillot Céline , Gómez Emyly González 
Published: April 2014

AbstractStructure 5N2 (initially named “Group A”) at Río Bec is the first ruin in the region to have been recorded and is its most important towered building. While it is reasonable to question the specific role such emblematic monumental structures played in the region's sociopolitical organization, precise data concerning their dating, construction history, and functions has been lacking. The recent study of Structure 5N2 has improved our understanding of this building type and of the structure itself, which combines a private residential sector (that astonishingly includes a central pyramid-temple) and a public space. The structure's construction history also reveals a great deal. Originally it consisted of only a tandem two-room residence constructed at roughlya.d.700–720. Arounda.d.830–850 the original residence was transformed into a large palace, which remained unfinished until abandonment just aftera.d.950. Analysis of the final building, replaced in the process of transformation to the settlement around Structure 5N2, also enables us to explore the social and economic dimensions of its dramatic but incomplete growth.
On the concept of probability
Authors: MUGUR-SCHÄCHTER MIOARA 
Published: April 2014

In this paper, we discuss the crucial but little-known fact that, as Kolmogorov himself claimed, the mathematical theory of probabilities cannot be applied to factual probabilistic situations. This is because it is nowhere specified how, for any given particular random phenomenon, we should construct, effectively and without circularity, the specific and stable distribution law that gives the individual numerical probabilities for the set of possible outcomes. Furthermore, we do not even know what significance we should attach to the simple assertion that such a distribution law “exists”. We call this problem Kolmogorov's aporia†.We provide a solution to this aporia in this paper. To do this, we first propose a general interpretation of the concept of probability on the basis of an example, and then develop it into a non-circular and effective general algorithm of semantic integration for the factual probability law involved in a specific factual probabilistic situation. The development of the algorithm starts from the fact that the concept of probability, unlike a statistic, does not apply to naturally pre-existing situations but is a conceptual artefact that ensures, locally in space and time, a predictability that is more stable and definite than that permitted by primary statistical data.The algorithm, which is constructed within a method of relativised conceptualisation, leads to a probability distribution expressed in rational numbers and involving a sort of quantification of the factual concept of probability. Furthermore, it also provides a definite meaning to the simple assertion that a factual probability law exists. We also show that the semantic integration algorithm is compatible with the weak law of large numbers.The results we give provide a complete solution to Kolmogorov's aporia. They also define a concept of probability that is explicitly organised into a semantic, epistemological and syntactic whole. In a broader context, our results can be regarded as a strong, pragmatic and operational specification of Karl Popper's propensity interpretation of probabilities.
Cognitive Functioning and Late-Life Depression
Authors: Koenig Aaron M. , Bhalla Rishi K. , Butters Meryl A. 
Published: March 2014

AbstractThis brief report provides an introduction to the topic of cognitive functioning in late-life depression (LLD). In addition to providing a review of the literature, we present a framework for understanding the heterogeneity of cognitive outcomes in this highly prevalent disorder. In addition, we discuss the relationship between LLD and dementia, and highlight the importance of regularly assessing cognitive functioning in older adults who present with depressive symptoms. If cognitive deficits are discovered during a neuropsychological assessment, we recommend referral to a geriatric psychiatrist or cognitive neurologist, for evaluation and treatment of the patient’s symptoms. (JINS, 2014,20, 1–7)
High-Energy Resolution Electron Energy-Loss Spectroscopy Study of Interband Transitions Characteristic to Single-Walled Carbon Nanotubes
Authors: Sato Yohei , Terauchi Masami 
Published: March 2014

AbstractAn electron energy-loss spectroscopic (EELS) study using a monochromator transmission electron microscope was conducted for investigating the dielectric response of isolated single-walled carbon nanotubes (SWCNTs) owing to interband transitions characteristic to chiral structures. Individual chiral structures of the SWCNTs were determined by electron diffraction patterns. EELS spectra obtained from isolated SWCNTs showed sharp peaks below π plasmon energy of 5 eV, which were attributed to the characteristic interband transitions of SWCNTs. In addition, unexpected shoulder structures were observed at the higher energy side of each sharp peak. Simulations of EELS spectra by using the continuum dielectric theory showed that an origin of the shoulder structures was because of the surface dipole mode along the circumference direction of the SWCNT. It was noticed that the electron excitation energies obtained by EELS were slightly higher than those of optical studies, which might be because of the inelastic scattering process with the momentum transfers. To interpret the discrepancy between the EELS and optical experiments, it is necessary to conduct more accurate simulation including the first principle calculation for the band structure of SWCNTs.
b-GENERALIZED DERIVATIONS OF SEMIPRIME RINGS HAVING NILPOTENT VALUES
Authors: TAMER KOŞAN M. , LEE TSIU-KWEN 
Published: March 2014

AbstractLet $\def \xmlpi #1{}\def \mathsfbi #1{\boldsymbol {\mathsf {#1}}}\let \le =\leqslant \let \leq =\leqslant \let \ge =\geqslant \let \geq =\geqslant \def \Pr {\mathit {Pr}}\def \Fr {\mathit {Fr}}\def \Rey {\mathit {Re}}R$ be a semiprime ring with extended centroid $C$ and with maximal right ring of quotients $Q_{mr}(R)$. Let $d{:}\ R\to Q_{mr}(R)$ be an additive map and $b\in Q_{mr}(R)$. An additive map $\delta {:}\ R\to Q_{mr}(R)$ is called a (left) $b$-generalized derivation with associated map $d$ if $\delta (xy)=\delta (x)y+bxd(y)$ for all $x, y\in R$. This gives a unified viewpoint of derivations, generalized derivations and generalized $\sigma $-derivations with an X-inner automorphism $\sigma $. We give a complete characterization of $b$-generalized derivations of $R$ having nilpotent values of bounded index. This extends several known results in the literature.
MODALITY AND AXIOMATIC THEORIES OF TRUTH I: FRIEDMAN-SHEARD
Authors: STERN JOHANNES 
Published: April 2014

AbstractIn this investigation we explore a general strategy for constructing modal theories where the modal notion is conceived as a predicate. The idea of this strategy is to develop modal theories over axiomatic theories of truth. In this first paper of our two part investigation we develop the general strategy and then apply it to the axiomatic theory of truth Friedman-Sheard. We thereby obtain the theory Modal Friedman-Sheard. The theory Modal Friedman-Sheard is then discussed from three different perspectives. First, we show that Modal Friedman-Sheard preserves theoremhood modulo translation with respect to modal operator logic. Second, we turn to semantic aspects and develop a modal semantics for the newly developed theory. Third, we investigate whether the modal predicate of Modal Friedman-Sheard can be understood along the lines of a proposal of Kripke, namely as a truth predicate modified by a modal operator.
Sectorial substrate-integrated half-mode near-field sensors for biological liquid characterization
Authors: Meyne Nora , Jacob Arne F. 
Published: April 2014

Two compact resonant near-field sensors are introduced for the characterization of aqueous solutions at 5 GHz. They are based on folded substrate-integrate circular half-mode resonators with a planar sensing tip. Owing to the planar design, the sensor is simple and cheap to manufacture, and a sample can be easily coupled to the resonator from the top. The operating principle of the sensor is explained and verified by both simulation and measurement. The radiation of the sensors is quantified by means of a quality factor analysis. Finally, a previously introduced calibration method based on the perturbation theory is applied to the sensors and its accuracy is improved by choosing more suitable reference materials.
RF-MEMS multi-mode-matching networks for GaN power transistors
Authors: Figur Sascha A. , van Raay Friedbert , Quay Rüdiger , Vietzorreck Larissa , Ziegler Volker 
Published: April 2014

This work presents radio-frequency-microelectromechanical-system (RF-MEMS)-based tunable input- and output-matching networks for a multi-band gallium nitride (GaN) power-amplifier applications. In the first part, circuit designs are shown and characterized for a fixed operation mode of the transistor, i.e. either a maximum-output-power- or a maximum-power-added-efficiency (PAE)-mode, which are finally combined into a multi-mode-matching network (M3N); the M3N allows to tune the operation mode of the transistor independently of its operational frequency. The matching networks are designed to provide optimum matching for the power amplifier at three to six different operating frequencies for maximum-output-power- and maximum-PAE-mode. In the frequency range from 3.5 to 8.5 GHz, return losses of 10 dB and higher were measured and insertion losses of 0.5–1.9 dB were demonstrated for the output-matching networks. Further characterizations were performed to test the dependency on the RF-input power, and no changes were observed up to power levels of 34 dBm when cold-switched.
Memory Impedance in TiO2 based Metal-Insulator-Metal Devices
Authors: Qingjiang Li , Khiat Ali , Salaoru Iulia , Papavassiliou Christos , Hui Xu , Prodromakis Themistoklis 
Published: March 2014

AbstractLarge attention has recently been given to a novel technology named memristor, for having the potential of becoming the new electronic device standard. Yet, its manifestation as the fourth missing element is rather controversial among scientists. Here we demonstrate that TiO2-based metal-insulator-metal devices are more than just a memory-resistor. They possess resistive, capacitive and inductive components that can concurrently be programmed; essentially exhibiting a convolution of memristive, memcapacitive and meminductive effects. We show how non-zero crossing current-voltage hysteresis loops can appear and we experimentally demonstrate their frequency response as memcapacitive and meminductive effects become dominant.
Design optimisation of metallic sub‐wavelength nanowire lasers
Authors: Sattar Zubaida A. , Shore Keith Alan , Wang Zengbo 
Published: April 2014

Design optimisation of metal‐clad cylindrical nanowire semiconductor lasers is undertaken. Attention is focused on structures having GaN as the material platform and utilising silver for the metal cladding. The lasing characteristics of such structures are explored using both the transfer matrix method and the finite element method for operating wavelengths from 330 to 830 nm and for metal cladding thicknesses in the range of 5–20 nm. Specifically, calculations are performed for the modal confinement factor, modal gain and device length across this wide parameter space. For representative structures, it is shown that lower‐order TE and TM mode lasing can be supported in devices having cavity lengths of the order of 2 and 18 µm, respectively.
Bistability of threshold in quantum dash‐in‐a‐well lasers
Authors: Harnedy Patrick E. , Osborne Simon , Joshi Siddharth , Lelarge François , O'Reilly Eoin P. 
Published: April 2014

The authors observe a bistability of threshold in a quantum dash ridge‐waveguide laser diode at temperatures below 230 K. A giant and sometimes negative characteristic temperature, T0, is measured at temperatures between 230 K and 320 K. They analyse the temperature dependent light‐current characteristics of this device, and a similar device with lower barriers, to gain an insight into the mechanism causing bistable behaviour. A rate equation model shows localisation and passive saturable absorption as the causes of the bistable behaviour in the higher barrier laser at low temperature. They find good qualitative agreement between the experimental and the theoretical results.
Ionospheric effects on three‐dimensional imaging of L‐band geosynchronous circular synthetic aperture radar
Authors: Kou Leilei , Xiang Maosheng , Wang Xiaoqing 
Published: April 2014

Circular synthetic aperture radar (SAR) imaging on the geosynchronous orbit has many potential advantages, such as high‐resolution three‐dimensional (3D) imaging and continuous surveillance of broad area. The mission considered is an L‐band geosynchronous circular SAR (GEOCSAR) with full aperture measurement. Since the integration time of GEOCSAR can be as long as 24 h, the orbit altitude is about 36 000 km and the coverage may reach 1/3 of the Earth's surface. The spatial and temporal variation of the ionosphere may impose significant effects on 3D imaging performance of GEOCSAR. The effects of ionospheric spatial variation including vertical and horizontal structure, the ionospheric turbulence and the ionospheric temporal variation are discussed. The analysis shows that the temporal variation of the ionospheric electron content during the synthetic aperture and the ionospheric turbulence may severely affect the GEOCSAR focusing performance on the XY plane. The vertical and horizontal structure of the ionosphere will cause image shift, and the dispersion effect is negligible.
Synthesis of size tunable gold nanoparticles polymeric hybrid based on molecular nanocages
Authors: Zhang Desuo , Xiong Jiaqing , Li Chenmei , Zhang Yan , Toh Guoyang W. , Lin Hong , Chen Yuyue 
Published: April 2014

A gold nanoparticles (NPs) polymeric hybrid was prepared through the reaction between HAuCl4 and polyamide network polymer (PNP). The PNP has three‐dimensional ‘nanocage’ structures and reactive amino groups incorporated in the molecular cages, so that the gold NPs can be in situ synthesised and fixed in the molecular nanocages. Owing to the volume confinement effect and the protection of the molecular nanocages, the size and the stability of the gold NPs can be controlled in a better manner. In addition, the size of the gold NPs can be tuned by changing the quantity of the precursor of the gold NPs encapsuled in the cages. Through this strategy, gold NPs with average diameters at 13.32, 11.41, 6.25 and 3.23 nm, were synthesised. These size tunable gold NPs polymeric hybrids may have a wide range of applications in many fields such as biomedicine, catalysis and optoelectronics.
Modified magnetite nanoparticles for colorimetric sensing of anionic surfactants in water
Authors: Wei Xiao‐Lan , Mo Zhi‐Hong 
Published: April 2014

Determination of anionic surfactants in water is classically based on the ion pairing of anionic surfactants with the methylene blue dye. As the optical absorption peaks of the dye and the ion pair overlap each other at 662 nm, it is required that the ion pair should be separated from the dye by chloroform extraction. In this reported work, it was found that the magnetite nanoparticles coated with poly(acrylic acid) could rapidly adsorb the methyl blue dyes in water and result in an obvious shift in optical absorption from 662 to 590 nm, which realises the spectral separation of the dye and the ion pair. Accordingly, using methyl blue dyes and the modified magnetite nanoparticles, anionic surfactants in water can be directly determined without extraction and/or separation. The lower limit of detection was 0.10 mg/l, and improved to 30 μg/l by magnetic removal of the nanoparticles. The functionalised magnetite nanoparticles allowed the development of a simple procedure for colorimetric sensing of anionic surfactants without the use of hazardous chlorinated organic solvents.
Spatial constraints control cell proliferation in tissues
Authors: Streichan Sebastian J. , Hoerner Christian R. , Schneidt Tatjana , Holzer Daniela , Hufnagel Lars 
Published: April 2014

Significance
Spatiotemporal coordination of cell growth underlies tissue development and disease. Mechanical feedback between cells has been proposed as a regulatory mechanism for growth control both in vivo and in cultured cells undergoing contact inhibition of proliferation. Evidence beyond theoretical and correlative observations falls short. In this study, we probe the impact of mechanical tissue perturbations on cell cycle progression by monitoring cell cycle dynamics of cells in tissues subject to acute changes in boundary conditions, as well as tissue stretching and compression. Taken together, we conclude that the ability of tissues to support cell cycle progression adapts to the available space through a memory-free control mechanism, which may coordinate proliferation patterns to maintain tissue homeostasis.