Comparing Google Scholar and ISI Web of Science for Earth Sciences

In order to measure the degree to which Google Scholar can compete with bibliographical databases, search results from this database is compared with Thomson’s ISI WoS (Institute for Scientific Information, Web of Science). For earth science literature 85% of documents indexed by ISI WoS were recalled by Google Scholar. The rank of records displayed in Google Scholar and ISI WoS, is compared by means of Spearman’s footrule. For impact measures the h-index is investigated. Similarities in measures were significant for the two sources.     

Slot antenna array synthesis using the infinitesimal dipole model technique: Theory and experiment

The present article proposes and validates a new general design methodology that can be used to automatically find proper positions and orientations of waveguide‐based radiating slots capable of realizing any given radiation beam profile. The new technique combines basic radiation theory and waveguide propagation theory in an analytical model that permits the prediction of the radiation characteristics of generic slots without the need to perform full‐wave numerical solution while completely avoiding using transmission‐line models or the slot impedance method. The analytical model is then used to implement a low‐cost objective function within a global optimization scheme and subsequently deployed to find optimum positions and orientations of clusters of radiating slots cut into the waveguide surface such that any desired beam pattern can be obtained, leading to very efficient and robust beamforming capability that can be applied to dynamic beamforming in real‐time scenarios like MIMO systems. The proposed design method is verified using both full‐wave numerical solution and experiment.     

Space‐time analysis of energy localization: A Poynting flow perspective with applications to pattern reconfigurable dipoles

In this paper, we explore the dynamics of electromagnetic energy, especially in the near‐field region of radiating antennas, from a fundamental perspective (ie, no limitations on antenna shape and nature of excitation signal) and identify some key future research directions. First, we provide a comprehensive critique of the frequency‐domain reactive energy and circuit‐theoretic Q‐factor based approach, which is predominantly adopted in literature. In this way, we emphasize on the importance of adopting a general time‐domain approach to characterize the near‐field electromagnetic energy of arbitrary antennas. Next, we revisit the inherent ambiguities associated with the Poynting power‐flux term in the context of electromagnetic energy, and point out the nonuniqueness of the reactive energy, conventionally obtained by subtracting the far‐field radiation density from the total electromagnetic energy density around antennas. Furthermore, we discuss the concept of Poynting localized energy and its potential integration with FDTD techniques, and investigate its space‐time behavior for a Yagi‐Uda principle based pattern reconfigurable dipole system.     

A secure framework of the surveillance video network integrating heterogeneous video formats and protocols

Recently, IT technologies are becoming focused on different traditional industries. The large scaled intelligent video surveillance system is one of them and it integrates a large number of digitalized CCTV [1] devices through the Web. However, existing video devices have been deployed for many years by different vendors as different models with different specifications. To integrate these heterogeneous devices, the centralized management server (CMS) and its clients need a specialized architecture to deal with different types of media encodings and connection protocols etc. In particular, well-defined access control mechanism is required for a large scaled surveillance video network. In this paper, we designed and implemented a server that incorporates the architecture integrating and delivering multiple video streams from different types of video devices to multiple clients and securing the access to the video streams.     

Photosensitizing properties of ionic porphyrins immobilized on functionalized solid polystyrene support

The photogeneration of singlet oxygen (¹O₂) by tetrasodium salt of meso‐tetrakis(4‐sulfonatophenyl)porphyrins (H₂TPPS) and some of its metal complexes (MTPPS; M = Cd²⁺, Zn²⁺), immobilized on cationically functionalized polystyrene (PS) beads, was studied. The generation of ¹O₂ was monitored by a N,N‐dimethyl‐4‐nitrosoaniline (RNO) bleaching assay. The rate of RNO bleaching was seen to be retarded in the presence of DABCO, a specific ¹O₂ scavanger, providing evidence for the involvement of ¹O₂ as an active intermediate. The relative efficiencies of the generation of ¹O₂, with respect to immobilized rose bengal (PS–RB), by different polymer‐supported porphyrins, were determined to be 0.29, 0.27, and 0.16 for PS–H₂TPPS, PS–ZnTPPS, and PS–CdTPPS, respectively. Binding of porphyrins to a polymer has been found to decrease the efficiency of the ¹O₂ generation, which could be attributed to the structural deformation of the appended porphyrins. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 3925–3930, 2003     

Formation and applications of stable 10 nm to 500 nm supramolecular porphyrinic materials

Nanoscaled materials of organic dyes are of interest for a variety of potential applications because of the rich photonic properties that this class of molecules can impart. One mode to form such nanoscaled materials is via self-organization and self-assembly, using reasonably well understood methods in supramolecular chemistry. But there are inherent complexities that arise from the use of organic-based supramolecular materials, including stability toward dioxygen, structural stability, and nanoarchitectures that may change with environmental conditions. Porphyrinoids have rich photonic properties yet are remarkably stable, have a rigid core, are readily functionalized, and metalation of the macrocycle can impart a plethora of optical, electronic, and magnetic properties. While there are many <10 nm porphyrinic assemblies, which may or may not self-organize into crystals, there is a paucity of 10–500 nm porphyrinic materials that can be isolated and stored. A variety of strategies towards the latter nanoscopic porphyrinic materials are discussed in terms of design, construction, and nanoarchitecture. The hierarchical structures include colloids, nanorods, nanotubes, nanorings, and nano-crystalline materials. This prolegomenon emphasizes the supramolecular chemistry, structure-stability, and structure-function relationships. The goal herein is to examine general trends and delineate general principles.     

An Algebraic Technique for Reliability Evaluation

An algebraic technique is proposed to obtain a simplified reliability expression of a general system. A success expression which directly gives the reliability expression, is formed and simplified by the procedure. The technique is equally efficient for simple and complex systems; yields computationally efficient reliability expressions; is routine (no decision making); yields an expression having a minimum number of product terms; and is easier than many existing techniques.     

Theory and Applications of Infinitesimal Dipole Models for Computational Electromagnetics

The recently introduced quantum particle swarm optimization (QPSO) algorithm is employed to find infinitesimal dipole models (IDM) for antennas with known near-fields (measured or computed). The IDM can predict accurately both the near-fields and the far-fields of the antenna. A theory is developed to explain the mechanism behind the IDM using the multipole expansion method. The IDM obtained from single frequency solutions is extrapolated over a frequency range around the design frequency. The method is demonstrated by analyzing conducting- and dielectric-type antennas. A calibration procedure is proposed to systematically implement infinitesimal dipoles within existing method of moment (MoM) codes. The interaction of the IDM with passive and active objects is studied through several examples. The IDM proved to predict the interaction efficiently. A closed-form expression for the mutual admittance between similar or dissimilar antennas, with arbitrary orientations and/or locations, is derived using the reaction theorem     

Scholarly publications beyond pay-walls: increased citation advantage for open publishing

First, we aim to determine the total amount of scholarly articles freely available on the internet. Second, we aim to prove whether there exists a citation advantage for open publishing. The total scholarly publication output of Norway is indexed in Cristin, the Current Information System in Norway. Based on these data, we searched Google Scholar by either DOIs or titles and denoted a document as open available (OAv), when a link to a full-text was provided. We analysed the extracted data by publishing year, citations, availability and provider. Based on additional information indexed in Cristin, we furthermore analysed the data by year, institution, publisher and discipline. We find that the total share of freely available articles is 68%. Articles not available belong to prestigious publishers such as Elsevier, Springer, Routledge and Universitetsforlaget (the largest Norwegian academic publisher), which may be particularly essential for scholars worldwide. The largest provider, according to Google Scholar’s main link provision, is ResearchGate. In addition, institutional repositories play a major role in posting free article versions. Articles belonging to natural sciences and technology, and medicine and health were more likely to be open than articles belonging to the social sciences and humanities. Their respective OAv-shares are 72, 58 and 55%. We find a clear citation advantage for open publishing; on average, these documents received twice as many citations, indicating that open access is the future in publishing. This study is limited to scholarly articles only. Books and book chapters, which are usual publication formats for the humanities and social sciences, are excluded. Results do therefore not adequately reflect the situation for these disciplines. Furthermore, this study is limited to documents freely available on the internet, independent of the “legal” status of the posted full-text. With the data at hand, we were not able to distinguish between gold, green, hybrid, purely pay-walled and illicitly posted documents. Usually, articles indexed in Web of Science or SCOPUS are objects of investigation. However, these databases do not sufficiently cover the humanities and social sciences, and therefore cannot be representative of the total scholarly article output. This study captures the total article output of a country, independent on discipline and provides new insight into open publishing.     

Spectral efficiency enhancement using an antenna‐based orthogonal frequency division multiaccess technique

An approach to enhance antenna spectral efficiency is proposed based on combining spacetime electromagnetic (EM) models of Tx/Rx antennas with orthogonal frequency division multiaccess (OFDM), leading to the EM‐OFDM, a technology capable of removing intersymbol interference (ISI) in high‐data rate communication links caused by the EM‐induced distortion antenna effects. The proposed approach differs from traditional OFDM in wireless communication in several aspects. First, the technique suggests a new decoupling approach by treating each given antenna transreceive device pair as a “stand‐alone channel” with its own distortion mechanisms considered separately from the propagation channel. Moreover, the deterministic distortion caused by the nonflat pure antenna EM filtration effects is exploited to carefully design a specialized OFDM transmission techniques based on the antenna parameters, not the multipath fading channels often invoked in conventional uses of OFDM methods. (The EM‐OFDM, however, can be combined with a traditional OFDM later if fading channels are present.) In this manner, a more efficient implementation of the wireless link equalization strategy may be enacted since the EM antenna origin of ISI is very different from the traditional propagation channel one. As a proof of concept, the proposed EM‐OFDM method is implemented for a single‐input‐single‐output link comprised of half‐wavelength linear wire antennas. A careful use of finite difference time‐domain to provide EM data allowed the construction of 64 decoupled “pure antenna OFDM subchannels.” Simulation results suggests that the antenna‐based OFDM system is capable of completely neutralizing all ISI effects caused by the limited antenna matching bandwidth of the transreceive wires, therefore, supporting considerably higher data rates with low symbol error rate (SER). A concrete evaluation of the SER using quadrature phase‐shift keying (QPSK) digital carrier modulation resulted in an increase of the effective antenna digital communication spectral efficiency by ratios up to 300%. Moreover, the EM‐OFDM error rate was found to be close to the ideal QPSK level or the maximum possible theoretical limit. Thus, combining detailed EM knowledge with standard signal processing methods can lead to considerable improvement in system design without modifying the antenna physical layout. The proposed approach is expected to play a role in the forthcoming 5G/6G and millimetre wave technology systems currently under development where there is a trend toward integration of EM and digital signal processing at the physical layer level.