bluuebunny/crossref_metadata_2025 huggingface dataset:
Joint wavelet‐based spectrum sensing and FBMC modulation for cognitive mmWave small cell networks
Authors: Hosseini Haleh , Anpalagan Alagan , Raahemifar Kaamran , Erkucuk Serhat , Habib Salman
Published: June 2016

Millimetre‐wave (mmWave) 5G communications is an emerging technology to enhance the capacity of existing systems by thousand‐fold improvement. Heterogeneous networks employing densely distributed small cells can optimise the available coverage and throughput of 5G systems. Efficiently utilising the spectrum bands by small cells is one of the approaches that will considerably increase the available data rate and capacity of the heterogeneous networks. This challenging task can be achieved by spectrum sensing capability of cognitive radios and new modulation techniques for data transmission. In this study, a wavelet‐based filter bank is proposed for spectrum sensing and modulation in 5G heterogeneous networks. The proposed technique can mitigate the spectral leakage and interference by adapting the subcarriers according to cognitive information provided by wavelet packet based spectrum sensing (WPSS) and lowering sidelobes using wavelet‐based filter bank multicarrier modulation. The performance improvement of WPSS compared with Fourier‐based spectrum sensing is verified in terms of power spectral density comparison and probabilities of detection and false alarm. Meanwhile, the bit error rate performance demonstrates the superiority of the proposed wavelet‐based system compared with its Fourier‐based counterpart over the 60 GHz mmWave channel.
Composite anti‐disturbance control for switched systems via mixed state‐dependent and time‐driven switching
Authors: Yang Dong , Zhao Jun
Published: June 2016

This study is concerned with the problem of composite anti‐disturbance control for switched linear systems with multiple disturbances. The authors' aim is to construct a disturbance observer to estimate the disturbance generated by an exogenous system, then design a composite controller based on the disturbance observer and a mixed state‐dependent and time‐driven switching law, such that the closed‐loop system is internally stable, and different types of disturbances are attenuated and rejected. First, a mixed switching law is designed, which guarantees a dwell time even when all subsystems are unstable. Then, a sufficient condition ensuring the solvability of the composite anti‐disturbance control problem is presented via multiple Lyapunov functions. Finally, the effectiveness of the proposed control design scheme is illustrated by its application to an aero‐engine, which cannot be handled by the existing approaches.
Model reference composite learning control without persistency of excitation
Authors: Pan Yongping , Zhang Jun , Yu Haoyong
Published: June 2016

Parameter convergence is desirable in adaptive control as it brings several attractive features, including accurate online modelling, exponential tracking, and robust adaptation without parameter drift. However, a strong persistent‐excitation (PE) condition must be satisfied to guarantee parameter convergence in the conventional adaptive control. This study proposes a model reference composite learning control strategy to guarantee parameter convergence without the PE condition. In the composite learning, an integral at a moving‐time window is applied to construct a prediction error, an integral transformation is derived for avoiding the time derivation of plant states in the calculation of the prediction error, and both the tracking error and the prediction error are applied to update parametric estimates. Global exponential stability of the closed‐loop system is established under an interval‐excitation condition which is much weaker than the PE condition. Compared with a concurrent learning technique that has the same aim as this study, the proposed composite learning technique avoids the usage of singular value maximisation and fixed‐point smoothing resulting in a considerable reduction of computational cost. Numerical results have verified effectiveness and superiority of the proposed control strategy.
Equivalent‐input‐disturbance‐based repetitive tracking control for Takagi–Sugeno fuzzy systems with saturating actuator
Authors: Selvaraj Palanisamy , Sakthivel Rathinasamy , Reza Karimi Hamid
Published: June 2016

This study investigates the output tracking problem for a class of Takagi–Sugeno fuzzy systems subject to periodic signals and actuator saturation via equivalent‐input‐disturbance (EID) technique. In particular, to ensure the periodic signals tracking, a state‐space repetitive control structure is considered. Further, the EID technique is utilised to improve the disturbance rejection performance without any prior knowledge of the disturbance and inverse dynamics of the plant. By constructing a suitable Lyapunov–Krasovskii functional and using the Wirtinger‐based integral inequality, a new set of sufficient conditions is derived in terms of linear matrix inequalities (LMIs) which ensures the stability of the addressed system. In addition to that by using a Lyapunov level set, saturation‐dependent Lyapunov function captures the real‐time information on the severity of actuator saturation and leads to less conservative estimate of the domain of attraction, which is based on the solution of an LMI optimisation problem. Moreover, the designed fuzzy repetitive controller is reliable in the sense that the stability and the satisfactory performance of the closed‐loop system are achieved not only under normal operation, but also in the presence of any actuator faults, saturation and dead zone. Finally, the proposed method is validated through two numerical examples to illustrate the effectiveness and superiority of the developed controller design.
Robust iterative learning control for batch processes with input delay subject to time‐varying uncertainties
Authors: Hao Shoulin , Liu Tao , Paszke Wojciech , Galkowski Krzysztof
Published: June 2016

A robust iterative learning control (ILC) method is proposed for industrial batch processes with input delay subject to time‐varying uncertainties, based on a two‐dimensional (2D) system description of batch process operation. To compensate the input delay, a 2D state predictor is established to predict the augmented system states, such that a 2D ILC design is developed for the ‘delay‐free’ 2D system based on using only the measured output errors of current and previous cycles. Delay‐dependent stability conditions for the resulting 2D system are established in terms of matrix inequalities by defining a comprehensive 2D Lyapunov–Krasovskii functional candidate along with free‐weighting matrices. By solving these matrix inequalities using a cone complementarity linearisation method, the ILC controller is explicitly derived together with an adjustable H infinity performance index. An important merit is that perfect tracking can be realised for a batch process with arbitrarily long input delay if the delay‐free part of the 2D system can be stabilised, in no presence of time‐varying uncertainties. Moreover, the time integral of tracking error can be added as an extended 2D system state for ILC design to eliminate steady‐state output error for all batches. An illustrative example of injection moulding process is given to demonstrate the effectiveness of the proposed method.
Sliding mode control for non‐linear systems by Takagi–Sugeno fuzzy model and delta operator approaches
Authors: Wang Jiahui , Gao Yabin , Qiu Jianbin , Ki Ahn Choon
Published: June 2016

This study considers the problem of adaptive sliding mode control for discrete‐time Takagi–Sugeno (T–S) fuzzy systems with actuator faults and external disturbances via the delta operator method. The delta operator approach is used to represent the discrete‐time non‐linear systems described by T–S fuzzy models. The actuator fault considered in this study is unknown and its fault‐deviation is also unknown. A reduced‐order system is utilised to design the sliding mode surface subject to linear matrix inequality constraint. By constructing the sliding mode surface, a novel adaptive sliding mode controller is designed to guarantee that the closed‐loop system is uniformly ultimately bounded. Finally, two practical examples are presented to show the effectiveness and applicability of the developed fault‐tolerant control scheme.
Dual mode antipodal Vivaldi antenna
Authors: Natarajan Rajesh , Kanagasabai Malathi , Gulam Nabi Alsath Mohammed
Published: June 2016

In this study, a dual mode antipodal Vivaldi antenna is developed to operate in ultra‐wideband and two narrowbands [global system for mobile communication (GSM) 1800, wireless local area network (WLAN)]. The antenna provides an impedance bandwidth of 9.7 GHz in wideband mode and 800 MHz, 280 MHz (WLAN, GSM 1800) in narrowband mode at −10 dB reference level. The antenna maintains symmetric radiation pattern in both the principal planes and provides minimum gain of 6 dB in both narrowband and wideband mode. Additionally, radar cross‐section performance of the antenna is calculated through simulation and discussed. Prototype antenna is fabricated with ideal switch and simulated results are validated through the measured results.
Arbitrary amplitude electrostatic wave propagation in a magnetized dense plasma containing helium ions and degenerate electrons
Authors: Mahmood S. , Sadiq Safeer , Haque Q. , Ali Munazza Z.
Published: June 2016

The obliquely propagating arbitrary amplitude electrostatic wave is studied in a dense magnetized plasma having singly and doubly charged helium ions with nonrelativistic and ultrarelativistic degenerate electrons pressures. The Fermi temperature for ultrarelativistic degenerate electrons described by N. M. Vernet [(Cambridge University Press, Cambridge, 2007), p. 57] is used to define ion acoustic speed in ultra-dense plasmas. The pseudo-potential approach is used to solve the fully nonlinear set of dynamic equations for obliquely propagating electrostatic waves in a dense magnetized plasma containing helium ions. The upper and lower Mach number ranges for the existence of electrostatic solitons are found which depends on the obliqueness of the wave propagation with respect to applied magnetic field and charge number of the helium ions. It is found that only compressive (hump) soliton structures are formed in all the cases and only subsonic solitons are formed for a singly charged helium ions plasma case with nonrelativistic degenerate electrons. Both subsonic and supersonic soliton hump structures are formed for doubly charged helium ions with nonrelativistic degenerate electrons and ultrarelativistic degenerate electrons plasma case containing singly as well as doubly charged helium ions. The effect of propagation direction on the soliton amplitude and width of the electrostatic waves is also presented. The numerical plots are also shown for illustration using dense plasma parameters of a compact star (white dwarf) from literature.
Optimal distributions for multiplex logistic networks
Authors: Solá Conde Luis E. , Used Javier , Romance Miguel
Published: June 2016

This paper presents some mathematical models for distribution of goods in logistic networks based on spectral analysis of complex networks. Given a steady distribution of a finished product, some numerical algorithms are presented for computing the weights in a multiplex logistic network that reach the equilibrium dynamics with high convergence rate. As an application, the logistic networks of Germany and Spain are analyzed in terms of their convergence rates.
Turbulence induced radial transport of toroidal momentum in boundary plasma of EAST tokamak
Authors: Zhao N. , Yan N. , Xu G. S. , Wang Z. X. , Wang H. Q. , Wang L. , Ding S. Y. , Chen R. , Chen L. , Zhang W. , Hu G. H. , Shao L. M.
Published: June 2016

Turbulence induced toroidal momentum transport in boundary plasma is investigated in H-mode discharge using Langmuir-Mach probes on EAST. The Reynolds stress is found to drive an inward toroidal momentum transport, while the outflow of particles convects the toroidal momentum outwards in the edge plasma. The Reynolds stress driven momentum transport dominates over the passive momentum transport carried by particle flux, which potentially provides a momentum source for the edge plasma. The outflow of particles delivers a momentum flux into the scrape-off layer (SOL) region, contributing as a momentum source for the SOL flows. At the L-H transitions, the outward momentum transport suddenly decreases due to the suppression of edge turbulence and associated particle transport. The SOL flows start to decelerate as plasma entering into H-mode. The contributions from turbulent Reynolds stress and particle transport for the toroidal momentum transport are identified. These results shed lights on the understanding of edge plasma accelerating at L-H transitions.
Effect of crystalline/amorphous interfaces on thermal transport across confined thin films and superlattices
Authors: Giri Ashutosh , Braun Jeffrey L. , Hopkins Patrick E.
Published: June 2016

We report on the thermal boundary resistances across crystalline and amorphous confined thin films and the thermal conductivities of amorphous/crystalline superlattices for Si/Ge systems as determined via non-equilibrium molecular dynamics simulations. Thermal resistances across disordered Si or Ge thin films increase with increasing length of the interfacial thin films and in general demonstrate higher thermal boundary resistances in comparison to ordered films. However, for films ≲3 nm, the resistances are highly dependent on the spectral overlap of the density of states between the film and leads. Furthermore, the resistances at a single amorphous/crystalline interface in these structures are much lower than those at interfaces between the corresponding crystalline materials, suggesting that diffusive scattering at an interface could result in higher energy transmissions in these systems. We use these findings, together with the fact that high mass ratios between amorphous and crystalline materials can lead to higher thermal resistances across thin films, to design amorphous/crystalline superlattices with very low thermal conductivities. In this regard, we study the thermal conductivities of amorphous/crystalline superlattices and show that the thermal conductivities decrease monotonically with increasing interface densities above 0.1 nm−1. These thermal conductivities are lower than that of the homogeneous amorphous counterparts, which alludes to the fact that interfaces non-negligibly contribute to thermal resistance in these superlattices. Our results suggest that the thermal conductivity of superlattices can be reduced below the amorphous limit of its material constituent even when one of the materials remains crystalline.
Magnetic tunnel junctions with a rock-salt-type Mg1−xTixO barrier for low resistance area product
Authors: Ikhtiar  , Kasai S. , Cheng P.-H. , Ohkubo T. , Takahashi Y. K. , Furubayashi T. , Hono K.
Published: June 2016

Ti-doped MgO (MTO) barriers were examined for polycrystalline magnetic tunnel junctions (MTJs) in combination with CoFeB ferromagnetic electrodes. The high tunneling magnetoresistance (TMR) ratio up to 240% and 160% was observed for the MTJs with Mg0.95Ti0.05O and Mg0.9Ti0.1O barriers after annealing at 450 °C. This high TMR ratio implies the presence of coherent tunneling. For a given thickness, MTJs with the MTO barriers were confirmed to have lower resistance-area product (RA) compared to those with the MgO barriers, suggesting the intrinsically lower barrier height of the MTO barriers. The MTO-based MTJs exhibit higher TMR ratio than those of the MgO-based MTJs for the RA range lower than 5 Ω μm2 as a consequence of thicker barriers and better wettability. This work has demonstrated the potential of the MTO barriers for low-RA MTJs.
Does borazine–water behave like benzene-water? A matrix isolation infrared and ab initio study
Authors: Mishra P. , Verma K. , Bawari D. , Viswanathan K. S.
Published: June 2016

Borazine is isoelectronic with benzene and is popularly referred to as inorganic benzene. The study of non-covalent interactions with borazine and comparison with its organic counterpart promises to show interesting similarities and differences. The motivation of the present study of the borazine-water interaction, for the first time, stems from such interesting possibilities. Hydrogen-bonded complexes of borazine and water were studied using matrix isolation infrared spectroscopy and quantum chemical calculations. Computations were performed at M06-2X and MP2 levels of theory using 6-311++G(d,p) and aug-cc-pVDZ basis sets. At both the levels of theory, the complex involving an N–H⋯O interaction, where the N–H of borazine serves as the proton donor to the oxygen of water was found to be the global minimum, in contrast to the benzene-water system, which showed an H–π interaction. The experimentally observed infrared spectra of the complexes corroborated well with our computations for the complex corresponding to the global minimum. In addition to the global minimum, our computations also located two local minima on the borazine-water potential energy surface. Of the two local minima, one corresponded to a structure where the water was the proton donor to the nitrogen of borazine, approaching the borazine ring from above the plane of the ring; a structure that resembled the global minimum in the benzene-water H–π complex. The second local minimum corresponded to an interaction of the oxygen of water with the boron of borazine, which can be termed as the boron bond. Clearly the borazine-water system presents a richer landscape than the benzene-water system.
Orientation correlation and local field in liquid nitrobenzene
Authors: Shelton David P.
Published: June 2016

Hyper-Rayleigh scattering (HRS) is sensitive to long-range molecular orientation correlation in isotropic liquids composed of dipolar molecules. Measurements of the polarization, angle, and spectral dependence for HRS from liquid nitrobenzene (NB) are analyzed to determine the NB molecular orientation correlations at long range. The longitudinal and transverse orientation correlation functions for r > 3 nm are BL(r) = (a/r)3 and BT(r) = − BL(r)/2, where a = 0.20 ± 0.01 nm. Measurements of HRS induced by dissolved ions are also analyzed and combined with molecular dynamics simulation and dielectric response results, to determine the molecular dipole moment μ = 3.90 ± 0.04 D, Kirkwood orientation correlation factor gK = 0.68 ± 0.02, and local field factor f(0) = 0.85 ± 0.04 × Onsager local field factor in liquid nitrobenzene.
Double nanosecond pulses generation in ytterbium fiber laser
Authors: Veiko V. P. , Lednev V. N. , Pershin S. M. , Samokhvalov A. A. , Yakovlev E. B. , Zhitenev I. Yu. , Kliushin A. N.
Published: June 2016

Double pulse generation mode for nanosecond ytterbium fiber laser was developed. Two sequential 60-200 ns laser pulses with variable delay between them were generated by acousto-optic modulator opening with continuous diode pumping. A custom radio frequency generator was developed to produce two sequential “opening” radio pulses with a delay of 0.2–1 μs. It was demonstrated that double pulse generation did not decrease the average laser power while providing the control over the laser pulse power profile. Surprisingly, a greater peak power in the double pulse mode was observed for the second laser pulse. Laser crater studies and plasma emission measurements revealed an improved efficiency of laser ablation in the double pulse mode.
Compression-amplified EMIC waves and their effects on relativistic electrons
Authors: Li L. Y. , Yu J. , Cao J. B. , Yuan Z. G.
Published: June 2016

During enhancement of solar wind dynamic pressure, we observe the periodic emissions of electromagnetic ion cyclotron (EMIC) waves near the nightside geosynchronous orbit (6.6RE). In the hydrogen and helium bands, the different polarized EMIC waves have different influences on relativistic electrons (>0.8 MeV). The flux of relativistic electrons is relatively stable if there are only the linearly polarized EMIC waves, but their flux decreases if the left-hand polarized (L-mode) EMIC waves are sufficiently amplified (power spectral density (PSD) ≥ 1 nT2/Hz). The larger-amplitude L-mode waves can cause more electron losses. In contrast, the R-mode EMIC waves are very weak (PSD < 1 nT2/Hz) during the electron flux dropouts; thus, their influence may be ignored here. During the electron flux dropouts, the relativistic electron precipitation is observed by POES satellite near the foot point (∼850 km) of the wave emission region. The quasi-linear simulation of wave-particle interactions indicates that the L-mode EMIC waves can cause the rapid precipitation loss of relativistic electrons, especially when the initial resonant electrons have a butterfly-like pitch angle distribution.
Space-time evolution of ejected plasma for the triggering of gas switch
Authors: Liu Shanhong , Liu Xuandong , Shen Xi , Feng Lei , Tie Weihao , Zhang Qiaogen
Published: June 2016

Ejected plasma has been widely applied to the discharge process of gas spark switches as a trigger technology, and the development process of ejected plasma has a direct and important effect on the discharge characteristics of gas switches. In this paper, both the injection characteristics and space-time evolution of ejected plasma for the triggering of gas spark switch with different stored energies, pulse polarities, and pressures are studied. The discharge characteristics and breakdown process of a gas switch ignited by ejected plasma under different working coefficients are also discussed briefly. The results show that stored energy has significant influence on the characteristics of ejected plasma. With the increase of stored energy, the propulsion mode of ejected plasma in the axial direction transforms from “plasmoid” to “plasma flow,” and the distribution of the ejected plasma goes through “cloud,” “core-cloud,” and “branch” in sequence. The velocity of ejected plasma under negative pulse polarity is obviously higher than that under positive pulse polarity, especially at the very beginning time. The radial dimensions of ejected plasma under two kinds of pulse polarities follow the similar varying pattern over time, which increase first and then decrease, assuming an inverted “U”-shaped curve. With the increase of pressure, the velocity of ejected plasma significantly decreases and the “branch” channels droop earlier. Applying the ejected plasma to the triggering of a gas switch, the switch can be triggered reliably in a much wide working coefficient range of 10%–90%. With the increase of working coefficient, the breakdown process of the switch translates from slow working mode to fast working mode, and the delay time reduces from tens of μs to hundreds of ns.
Highly conductive grain boundaries in copper oxide thin films
Authors: Deuermeier Jonas , Wardenga Hans F. , Morasch Jan , Siol Sebastian , Nandy Suman , Calmeiro Tomás , Martins Rodrigo , Klein Andreas , Fortunato Elvira
Published: June 2016

High conductivity in the off-state and low field-effect mobility compared to bulk properties is widely observed in the p-type thin-film transistors of Cu2O, especially when processed at moderate temperature. This work presents results from in situ conductance measurements at thicknesses from sub-nm to around 250 nm with parallel X-ray photoelectron spectroscopy. An enhanced conductivity at low thickness is explained by the occurrence of Cu(II), which is segregated in the grain boundary and locally causes a conductivity similar to CuO, although the surface of the thick film has Cu2O stoichiometry. Since grains grow with an increasing film thickness, the effect of an apparent oxygen excess is most pronounced in vicinity to the substrate interface. Electrical properties of Cu2O grains are at least partially short-circuited by this effect. The study focuses on properties inherent to copper oxide, although interface effects cannot be ruled out. This non-destructive, bottom-up analysis reveals phenomena which are commonly not observable after device fabrication, but clearly dominate electrical properties of polycrystalline thin films.
Time-resolved scanning Kerr microscopy of flux beam formation in hard disk write heads
Authors: Valkass Robert A. J. , Spicer Timothy M. , Burgos Parra Erick , Hicken Robert J. , Bashir Muhammad A. , Gubbins Mark A. , Czoschke Peter J. , Lopusnik Radek
Published: June 2016

To meet growing data storage needs, the density of data stored on hard disk drives must increase. In pursuit of this aim, the magnetodynamics of the hard disk write head must be characterized and understood, particularly the process of “flux beaming.” In this study, seven different configurations of perpendicular magnetic recording (PMR) write heads were imaged using time-resolved scanning Kerr microscopy, revealing their detailed dynamic magnetic state during the write process. It was found that the precise position and number of driving coils can significantly alter the formation of flux beams during the write process. These results are applicable to the design and understanding of current PMR and next-generation heat-assisted magnetic recording devices, as well as being relevant to other magnetic devices.
Two-dimensional electron gas in GaAs/SrHfO3 heterostructure
Authors: Wang Jianli , Yuan Mengqi , Tang Gang , Li Huichao , Zhang Junting , Guo Sandong
Published: June 2016

The III-V/perovskite-oxide system can potentially create new material properties and new device applications by combining the rich properties of perovskite-oxides together with the superior optical and electronic properties of III-Vs. The structural and electronic properties of the surface and interface are studied using first-principles calculations for the GaAs/SrHfO3 heterostructure. We investigate the specific adsorption sites and the atomic structure at the initial growth stage of GaAs on the SrHfO3 (001) substrate. Ga and As adsorption atoms preferentially adsorb at the top sites of oxygen atoms under different coverage. The energetically favorable interfaces are presented among the atomic arrangements of the GaAs/SrHfO3 interfaces. Our calculations predict the existing of the two-dimensional electron gas in the GaAs/SrHfO3 heterostructure.
Influence of energy structure on recombination lifetime in GaAs/AlGaAs multilayers
Authors: Tavares B. G. M. , Tito M. A. , Pusep Yu. A.
Published: June 2016

The processes of recombination of the photoexcited electron-hole pairs were studied in GaAs/AlGaAs weakly coupled multiple quantum wells, where the photoluminescence emission was composed of the contributions from the Γ−Γ and Γ−X conduction band minibands. Remarkable enhancement of the recombination time was observed when the magnetic field caused depopulation of the higher energy Γ−X miniband. The observed effect is attributed to the magnetic field induced variation of the electron density of states.
Wavelength-selective ultraviolet (Mg,Zn)O photodiodes: Tuning of parallel composition gradients with oxygen pressure
Authors: Zhang Zhipeng , von Wenckstern Holger , Lenzner Jörg , Grundmann Marius
Published: June 2016

We report on ultraviolet photodiodes with integrated optical filter based on the wurtzite (Mg,Zn)O thin films. Tuning of the bandgap of filter and active layers was realized by employing a continuous composition spread approach relying on the ablation of a single segmented target in pulsed-laser deposition. Filter and active layers of the device were deposited on opposite sides of a sapphire substrate with nearly parallel compositional gradients. Ensure that for each sample position the bandgap of the filter layer blocking the high energy radiation is higher than that of the active layer. Different oxygen pressures during the two depositions runs. The absorption edge is tuned over 360 meV and the spectral bandwidth of photodiodes is typically 100 meV and as low as 50 meV.
Operation of an InAs quantum-dot embedded GaAs photonic crystal slab waveguide laser by using two-photon pumping for photonics integrated circuits
Authors: Oda H. , Yamanaka A. , Ozaki N. , Ikeda N. , Sugimoto Y.
Published: June 2016

The development of small sized laser operating above room temperature is important in the realization of optical integrated circuits. Recently, micro-lasers consisting of photonic crystals (PhCs) and whispering gallery mode cavities have been demonstrated. Optically pumped laser devices could be easily designed using photonic crystal-slab waveguides (PhC-WGs) with an air-bridge type structure. In this study, we observe lasing at 1.3μm from two-photon pumped InAs-quantum-dots embedded GaAs PhC-WGs above room temperature. This type of compact laser shows promise as a new light source in ultra-compact photonics integrated circuits.
Analytical solution for the diffusion of a capacitor discharge generated magnetic field pulse in a conductor
Authors: Grants Ilmārs , Bojarevičs Andris , Gerbeth Gunter
Published: June 2016

Powerful forces arise when a pulse of a magnetic field in the order of a few tesla diffuses into a conductor. Such pulses are used in electromagnetic forming, impact welding of dissimilar materials and grain refinement of solidifying alloys. Strong magnetic field pulses are generated by the discharge current of a capacitor bank. We consider analytically the penetration of such pulse into a conducting half-space. Besides the exact solution we obtain two simple self-similar approximate solutions for two sequential stages of the initial transient. Furthermore, a general solution is provided for the external field given as a power series of time. Each term of this solution represents a self-similar function for which we obtain an explicit expression. The validity range of various approximate analytical solutions is evaluated by comparison to the exact solution.
Disruption of the AMPK–TBC1D1 nexus increases lipogenic gene expression and causes obesity in mice via promoting IGF1 secretion
Authors: Chen Liang , Chen Qiaoli , Xie Bingxian , Quan Chao , Sheng Yang , Zhu Sangsang , Rong Ping , Zhou Shuilian , Sakamoto Kei , MacKintosh Carol , Wang Hong Yu , Chen Shuai
Published: June 2016

Significance

Excess energy intake and physical inactivity are two major factors causing obesity, but the underlying mechanisms have not been fully understood. Both excess energy intake and physical inactivity increase cellular energy status that is monitored by the energy-sensing AMP-activated protein kinase (AMPK). We demonstrate that the AMPK–tre-2/USP6, BUB2, cdc16 domain family member 1 (the TBC domain is the GTPase activating protein domain) (TBC1D1) signaling nexus regulates insulin-like growth factor 1 (IGF1) secretion. Disruption of this AMPK–TBC1D1 signaling nexus in mice enhances lipogenic gene expression via promoting IGF1 secretion, causes obesity, and eventually leads to development of metabolic syndrome. These findings reveal a novel regulatory mechanism that links energy status to development of obesity via control of IGF1 secretion.
Amino acid sequence repertoire of the bacterial proteome and the occurrence of untranslatable sequences
Authors: Navon Sharon Penias , Kornberg Guy , Chen Jin , Schwartzman Tali , Tsai Albert , Puglisi Elisabetta Viani , Puglisi Joseph D. , Adir Noam
Published: June 2016

Significance

Some peptide sequences are underrepresented or completely excluded from proteomes because they interfere with protein synthesis. Interference arises from interaction with the peptide exit tunnel of the ribosome. The low frequency of such interactions is an important, previously unrecognized feature of the ribosome.
Identification of shared TCR sequences from T cells in human breast cancer using emulsion RT-PCR
Authors: Munson Daniel J. , Egelston Colt A. , Chiotti Kami E. , Parra Zuly E. , Bruno Tullia C. , Moore Brandon L. , Nakano Taizo A. , Simons Diana L. , Jimenez Grecia , Yim John H. , Rozanov Dmitri V. , Falta Michael T. , Fontenot Andrew P. , Reynolds Paul R. , Leach Sonia M. , Borges Virginia F. , Kappler John W. , Spellman Paul T. , Lee Peter P. , Slansky Jill E.
Published: June 2016

Significance

The essence of the adaptive immune response depends on the specificity of antigen receptors. This report identifies shared alpha–beta T-cell receptor (TCR) pairs from the tissues of HLA-A2
+
patients with breast cancer and control donors. Using an emulsion-based RT-PCR assay, we analyzed TCR sequences from tissues ex vivo. We identified multiple TCR pairs shared between tumors, but not control samples. Although recent reports have concluded that anticancer T-cell responses depend on patient-specific mutation-associated neoantigens, this study provides evidence that T cells also recognize shared antigens. This approach has broad application to a variety of research questions where the end goal is to examine T-cell repertoires and/or identify T-cell antigens.
Comparison of droplet digital PCR to real-time PCR for quantification of hepatitis B virus DNA
Authors: Tang Hui , Cai Qingchun , Li Hu , Hu Peng
Published: June 2016

Quantitative real-time PCR (qPCR) has been widely implemented for clinical hepatitis B viral load testing, but a lack of standardization and relatively poor precision hinder its usefulness. Droplet digital PCR (ddPCR) is a promising tool that offers high precision and direct quantification. In this study, we compared the ddPCR QX100 platform by Bio-Rad with the CFX384 Touch Real-Time PCR Detection System (Bio-Rad, USA) to detect serial plasmid DNA dilutions of known concentrations as well as HBV DNA extracted from patient serum samples. Both methods showed a high degree of linearity and quantitative correlation. However, ddPCR assays generated more reproducible results and detected lower copy numbers than qPCR assays. Patient sample quantifications by ddPCR and qPCR were highly agreeable based on the Bland–Altman analysis. Collectively, our findings demonstrate that ddPCR offers improved analytical sensitivity and specificity for HBV measurements and is suitable for clinical HBV detection.
Diffusion and decoupling in the world heritage movement: exploring global/local tensions in Africa
Authors: Elliott Michael A. , Schmutz Vaughn
Published: June 2016

A common critique of world society theory is that it overemphasises processes of institutional expansion and isomorphism, and underemphasises instances of decoupling and local variation. We address this concern head-on through an analysis of the world heritage movement. On the one hand, we detail how this movement has expanded into a global institution with highly standardised procedures for evaluating the ‘outstanding universal value’ of cultural and natural sites around the world. On the other hand, we detail how these procedures involve rational-scientific assumptions about evaluation that lead to regional inequality, hindering the ability of less developed countries to successfully nominate, inscribe and manage world heritage sites. With a specific focus on African countries, we identify how decoupling occurs in two distinct ways that hamper their participation in the world heritage movement: (1) a lack of scientific and technical expertise and (2) a cultural mismatch between local and global conceptions of universal value.
Network and Multilayer Network Approaches to Understanding Human Brain Dynamics
Authors: Muldoon Sarah Feldt , Bassett Danielle S.
Published: June 2016

Network neuroscience provides a systems approach to the study of the brain and enables the examination of interactions measured at different temporal and spatial scales. We review current methods to quantify the structure of brain networks and compare that structure across different clinical cohorts, cognitive states, and subjects. We further introduce the emerging mathematical concept of multilayer networks and describe the advantages of this approach to model changing brain dynamics over time. We conclude by offering several concrete examples of how multilayer network approaches to neuroimaging data provide novel insights into brain structure and evolving function.
Scientific Explanation: Putting Communication First
Authors: Potochnik Angela
Published: June 2016

Scientific explanations must bear the proper relationship to the world: they must depict what, out in the world, is responsible for the explanandum. But explanations must also bear the proper relationship to their audience: they must be able to create human understanding. With few exceptions, philosophical accounts of explanation either ignore entirely the relationship between explanations and their audience or else demote this consideration to an ancillary role. In contrast, I argue that considering an explanation’s communicative role is crucial to any satisfactory account of explanation.
Is There A Monist Theory of Causal and Noncausal Explanations? The Counterfactual Theory of Scientific Explanation
Authors: Reutlinger Alexander
Published: June 2016

The goal of this paper is to develop a counterfactual theory of explanation (CTE). The CTE provides a monist framework for causal and noncausal explanations, according to which both causal and noncausal explanations are explanatory by virtue of revealing counterfactual dependencies between the explanandum and the explanans. I argue that the CTE is applicable to two paradigmatic examples of noncausal explanations: Euler’s explanation and renormalization group explanations of universality.
Three Tales of Scientific Success
Authors: Massimi Michela
Published: June 2016

Success-to-truth inferences have been the realist stronghold for a long time. Scientific success is the parameter by which realists claim to discern approximately true theories from false ones. But scientific success needs to be probed a bit deeper. In this article, I tell three tales of scientific success, by considering in turn success from nowhere, success from here now, and success from within. I argue for a suitable version of success from within that can do justice to the historically situated nature of our scientific knowledge. The outcome is a new way of thinking about success-to-truth inferences along perspectivalist lines.
Reproduction in Complex Life Cycles: Toward a Developmental Reaction Norms Perspective
Authors: Griesemer James
Published: June 2016

Biological reproduction is a material process of intertwined, recursive propagule generation and development, assuming that development produces simple life cycles. Most organisms, however, have more or less complex life cycles. Here, I attempt to reconcile recent articulations of a reproducer account with traditional approaches to complex life cycles by generalizing genetic demarcation criteria for life cycle generations in terms of the “scaffolded” development of hybrid reproducers. I argue that scaffolding provides a general method for identifying developmental bottlenecks and suggests in turn a new way of understanding developmental reaction norms.
On Hamilton’s Rule and Inclusive Fitness Theory with Nonadditive Payoffs
Authors: Okasha Samir
Published: June 2016

Hamilton’s theory of inclusive fitness is a widely used framework for studying the evolution of social behavior, but controversy surrounds its status. Hamilton originally derived his famous rb > c rule for the spread of a social gene by assuming additivity of costs and benefits. However, it has recently been argued that the additivity assumption can be dispensed with, so long as the −c and b terms are suitably defined, as partial regression coefficients. I argue that this way of generalizing Hamilton’s rule to the nonadditive case, while formally correct, faces conceptual problems.
The Evolution of Guilt: A Model-Based Approach
Authors: O’Connor Cailin
Published: June 2016

Using evolutionary game theory, I consider how guilt can provide individual fitness benefits to actors both before and after bad behavior. This supplements recent work by philosophers on the evolution of guilt with a more complete picture of the relevant selection pressures.
On the Limits of Causal Modeling: Spatially-Structurally Complex Biological Phenomena
Authors: Kaiser Marie I.
Published: June 2016

This article examines the adequacy of causal graph theory as a tool for modeling biological phenomena. I argue that the causal graph approach reaches its limits when it comes to modeling biological phenomena that involve complex spatial and chemical-structural relations. Using a case study from molecular biology, I show why causal graph models fail to adequately represent and explain biological phenomena of this kind. The inadequacy of these models is due to their failure to include relevant spatial-structural information in a way that does not render the models nonexplanatory, unmanageable, or inconsistent with basic assumptions of causal graph theory.
How to Model Mechanistic Hierarchies
Authors: Casini Lorenzo
Published: June 2016

Mechanisms are usually viewed as hierarchical, with lower levels of a mechanism influencing, and decomposing, its higher-level behavior. To draw quantitative predictions from a model of a mechanism, the model must capture this hierarchical aspect. Recursive Bayesian networks (RBNs) were put forward by Lorenzo Casini et al. as a means to model mechanistic hierarchies by decomposing variables into their constituting causal networks. The proposal was criticized by Alexander Gebharter. He proposes an alternative formalism, which instead decomposes arrows. Here, I defend RBNs from the criticism and argue that they offer a better representation of mechanistic hierarchies than the rival account.
Which Curie’s Principle?
Authors: Castellani Elena , Ismael Jenann
Published: June 2016

Is there more than one “Curie’s principle”? How far are different formulations legitimate? What are the aspects that make it so scientifically fruitful? This article is devoted to exploring these questions. We begin by discussing Curie’s original 1894 article. Then, we consider the way that the discussion of the principle took shape from early commentators to its modern form. We say why we think that the modern focus on the interstate version of the principle loses sight of some of the most significant applications of the principle. Finally, we address criticisms of the principle put forward by John Norton and Bryan Roberts.
On the Relation between Dualities and Gauge Symmetries
Authors: de Haro Sebastian , Teh Nicholas , Butterfield Jeremy
Published: June 2016

We make two points about dualities in string theory. The first point is that the conception of duality, which we will discuss, meshes with two dual theories being ‘gauge related’ in the general philosophical sense of being physically equivalent. The second point is a result about gauge/gravity duality that shows its relation to gauge symmetries to be subtler than one might expect: each of a certain class of gauge symmetries in the gravity theory, that is, diffeomorphisms, is related to a position-dependent symmetry of the gauge theory.
CCEM key comparison CCEM.RF-K23.F
Authors: Guerrieri J , Coder J , MacReynolds K , Tamura D , Gentle D G , Beardmore A , Eio C , Budovsky I , Ji Y , Warner F M , Wei-long W , Donglin M , Dražil K , Sage Y Le , Allal D , Hirose M , Kurokawa S , Komiyama K , Sergey K , Sergey N , Kang J-S , Kang N-W , Fast L , Karlsson K , Carlsson Jan , Pythoud F , ÇAKIR S , Cetintas M
Published: June 2016

The CCEM international antenna gain comparison CCEM.RF- K23.F was initiated by the Working Group on Radio Frequency quantities (GT_RF) on the Consultative Committee for Electricity and Magnetism. This key comparison report presents results of measurements of on-axis gain of two Ku-band pyramidal horns at 12.4, 15, and 18 GHz. Participants making corrections for mismatch were asked to provide a table of the real and imaginary parts of the reflection coefficients of the antennas. Optionally, participants could measure the swept frequency gain from 12.4 to 18 GHz. Twelve national laboratories participated. The National Institute of Standards and Technology from the United States was the pilot lab. The purpose of the comparison was to evaluate the consistency between the participating laboratories in the measurement of the boresight gain of horn antennas in the WR-62 band.

Main text

To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/.

The final report has been peer-reviewed and approved for publication by the CCEM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).
Comparison of the Josephson Voltage Standards of the DMDM and the BIPM (part of the ongoing BIPM key comparison BIPM.EM-K10.b)
Authors: Solve S , Chayramy R , Stock M , Pantelic-Babic J , Sofranac Z , Vujovic T Cincar
Published: June 2016

A comparison of the Josephson array voltage standards of the Bureau International des Poids et Mesures (BIPM) and the Directorate of Measures and Precious Metals (DMDM), Belgrade, Serbia, was carried out in June 2015 at the level of 10 V. For this exercise, options A and B of the BIPM.EM-K10.b comparison protocol were applied. Option B required the BIPM to provide a reference voltage for measurement by the DMDM using its Josephson standard with its own measuring device. Option A required the DMDM to provide a reference voltage with its Josephson voltage standard for measurement by the BIPM using an analogue nanovoltmeter and associated measurement loop. Since no sufficiently stable voltage could be achieved in this configuration, a digital detector was used. In all cases the BIPM array was kept floating from ground.

The final results were in good agreement within the combined relative standard uncertainty of 1.5 parts in 1010 for the nominal voltage of 10 V.

Main text

To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/.

The final report has been peer-reviewed and approved for publication by the CCEM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).
Final report on APMP.T-K7 key comparison of water triple point cells
Authors: Tsai S F , White R , Tamba J , Yamazawa K , Ho M K , Tsui C M , Zaid G , Achmadi A , Gam K S , Othman H , Ali N M , Yuan K H , Shaochun Y , Liedberg H , Yaokulbodee C
Published: June 2016

APMP.T-K7, was held from February 2008 to September 2009 to compare the national realizations of the water triple point among eleven NMIs. To reach the objective, each participating laboratory sent a transfer cell to CMS and stated a value for the temperature difference of the transfer cell, relative to the corresponding national standard, representing 273.16 K.

CMS (Taiwan) organized the comparison, with the support from co-pilot institutes MSL (New Zealand) and NMIJ (Japan). The other eight participating laboratories included NMIA, SCL, KIM-LIPI, KRISS, NMIM/SIRIM, NMC, NMISA, and NIMT.

This report presents the results of the TPW comparison, gives detailed information about the measurements made at the CMS and at the participating laboratories, and aims to link the results of APMP.T-K7 to CCT-K7. The results of this key comparison are also represented in the form of degrees of equivalence for the purposes of the MRA.

Main text

To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/.

The final report has been peer-reviewed and approved for publication by the CCT, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).