54,570 research outputs found

    Channels of published research communication used by Malaysian authors in computer science and information technology

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    Analyse 389 records retrieved from Inspec (1990-1999), Compendex (1987-1999) and IEL (IEE/IEEE Electronic library)(1987-1999). The records comprised 159 journal articles, 229 conference papers and 1 monograph chapter. The subject coverage was computer science and information technology. The yearly output of Malaysian publications indicated a gentle upward trend. The highest contributions was 87 published in 1997. The channels used to publish differ slightly from the norm for scientists. Conference papers were preferred to journal articles. The spread of conference papers used to publish indicate three zonal distributions; the nucleus, moderate and low productivity in the ratio of 19 : 41 : 88, leading to a clustering index of 2.15. This shows that Malaysian conference contributions were concentrated in a few proceedings. No clear core journals can be identified for the journal articles and contributions were distributed in a wide variety of journal titles. Malaysian Journal of Computer Science published the highest number of journal articles. More than 83 of the articles were published in journals from the UK, USA, the Netherlands and Malaysia

    Electron-Phonon Interactions for Optical Phonon Modes in Few-Layer Graphene

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    We present a first-principles study of the electron-phonon (e-ph) interactions and their contributions to the linewidths for the optical phonon modes at Γ\Gamma and K in one to three-layer graphene. It is found that due to the interlayer coupling and the stacking geometry, the high-frequency optical phonon modes in few-layer graphene couple with different valence and conduction bands, giving rise to different e-ph interaction strengths for these modes. Some of the multilayer optical modes derived from the Γ\Gamma-E2gE_{2g} mode of monolayer graphene exhibit slightly higher frequencies and much reduced linewidths. In addition, the linewidths of K-A1A'_1 related modes in multilayers depend on the stacking pattern and decrease with increasing layer numbers.Comment: 6 pages,5 figures, submitted to PR

    A Revised Effective Temperature Scale for the Kepler Input Catalog

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    We present a catalog of revised effective temperatures for stars observed in long-cadence mode in the Kepler Input Catalog (KIC). We use SDSS griz filters tied to the fundamental temperature scale. Polynomials for griz color-temperature relations are presented, along with correction terms for surface gravity effects, metallicity, and statistical corrections for binary companions or blending. We compare our temperature scale to the published infrared flux method (IRFM) scale for VJKs in both open clusters and the Kepler fields. We find good agreement overall, with some deviations between (J - Ks)-based temperatures from the IRFM and both SDSS filter and other diagnostic IRFM color-temperature relationships above 6000 K. For field dwarfs we find a mean shift towards hotter temperatures relative to the KIC, of order 215 K, in the regime where the IRFM scale is well-defined (4000 K to 6500 K). This change is of comparable magnitude in both color systems and in spectroscopy for stars with Teff below 6000 K. Systematic differences between temperature estimators appear for hotter stars, and we define corrections to put the SDSS temperatures on the IRFM scale for them. When the theoretical dependence on gravity is accounted for we find a similar temperature scale offset between the fundamental and KIC scales for giants. We demonstrate that statistical corrections to color-based temperatures from binaries are significant. Typical errors, mostly from uncertainties in extinction, are of order 100 K. Implications for other applications of the KIC are discussed.Comment: Corrected for sign flip errors in the gravity corrections. Erratum to this paper is attached in Appendix. Full version of revised Table 7 can be found at http://home.ewha.ac.kr/~deokkeun/kic/sdssteff_v2.dat.g

    Towards Analyzing Semantic Robustness of Deep Neural Networks

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    Despite the impressive performance of Deep Neural Networks (DNNs) on various vision tasks, they still exhibit erroneous high sensitivity toward semantic primitives (e.g. object pose). We propose a theoretically grounded analysis for DNN robustness in the semantic space. We qualitatively analyze different DNNs' semantic robustness by visualizing the DNN global behavior as semantic maps and observe interesting behavior of some DNNs. Since generating these semantic maps does not scale well with the dimensionality of the semantic space, we develop a bottom-up approach to detect robust regions of DNNs. To achieve this, we formalize the problem of finding robust semantic regions of the network as optimizing integral bounds and we develop expressions for update directions of the region bounds. We use our developed formulations to quantitatively evaluate the semantic robustness of different popular network architectures. We show through extensive experimentation that several networks, while trained on the same dataset and enjoying comparable accuracy, do not necessarily perform similarly in semantic robustness. For example, InceptionV3 is more accurate despite being less semantically robust than ResNet50. We hope that this tool will serve as a milestone towards understanding the semantic robustness of DNNs.Comment: Presented at European conference on computer vision (ECCV 2020) Workshop on Adversarial Robustness in the Real World ( https://eccv20-adv-workshop.github.io/ ) [best paper award]. The code is available at https://github.com/ajhamdi/semantic-robustnes

    Atomic-scale combination of germanium-zinc nanofibers for structural and electrochemical evolution

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    Alloys are recently receiving considerable attention in the community of rechargeable batteries as possible alternatives to carbonaceous negative electrodes; however, challenges remain for the practical utilization of these materials. Herein, we report the synthesis of germanium-zinc alloy nanofibers through electrospinning and a subsequent calcination step. Evidenced by in situ transmission electron microscopy and electrochemical impedance spectroscopy characterizations, this one-dimensional design possesses unique structures. Both germanium and zinc atoms are homogenously distributed allowing for outstanding electronic conductivity and high available capacity for lithium storage. The as-prepared materials present high rate capability (capacity of similar to 50% at 20 C compared to that at 0.2 C-rate) and cycle retention (73% at 3.0 C-rate) with a retaining capacity of 546 mAh g(-1) even after 1000 cycles. When assembled in a full cell, high energy density can be maintained during 400 cycles, which indicates that the current material has the potential to be used in a large-scale energy storage system
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