Mixed numerologies interference analysis and inter-numerology interference cancellation for windowed OFDM systems

Extremely diverse service requirements are one of the critical challenges for the upcoming fifth-generation (5G) radio access technologies. As a solution, mixed numerologies transmission is proposed as a new radio air interface by assigning different numerologies to different subbands. However, coexistence of multiple numerologies induces the inter-numerology interference (INI), which deteriorates the system performance. In this paper, a theoretical model for INI is established for windowed orthogonal frequency division multiplexing (W-OFDM) systems. The analytical expression of the INI power is derived as a function of the channel frequency response of interfering subcarrier, the spectral distance separating the aggressor and the victim subcarrier, and the overlapping windows generated by the interferer's transmitter windows and the victim's receiver window. Based on the derived INI power expression, a novel INI cancellation scheme is proposed by dividing the INI into a dominant deterministic part and an equivalent noise part. A soft-output ordered successive interference cancellation (OSIC) algorithm is proposed to cancel the dominant interference, and the residual interference power is utilized as effective noise variance for the calculation of log-likelihood ratios (LLRs) for bits. Numerical analysis shows that the INI theoretical model matches the simulated results, and the proposed interference cancellation algorithm effectively mitigates the INI and outperforms the state-of-the-art W-OFDM receiver algorithms

An all fiber source of frequency entangled photon pairs

We present an all fiber source of frequency entangled photon pairs by using four wave mixing in a Sagnac fiber loop. Special care is taken to suppress the impurity of the frequency entanglement by cooling the fiber and by matching the polarization modes of the photon pairs counter-propagating in the fiber loop. Coincidence detection of signal and idler photons, which are created in pair and in different spatial modes of the fiber loop, shows the quantum interference in the form of spatial beating, while the single counts of the individual signal (idler) photons keep constant. When the production rate of photon pairs is about 0.013 pairs/pulse, the envelope of the quantum interference reveals a visibility of $(95\pm 2)$, which is close to the calculated theoretical limit 97.4%Comment: 11 pages, 6 figures, to appear in Phys. Rev.

The antioxidant effect of Asparagus cochinchinensis (Lour.) Merr. shoot in d-galactose induced mice aging model and in vitro

AbstractBackgroundAn increasing number of plant components and their extracts have been shown to have beneficial health effects in humans. We aimed to explore the antioxidant effects of the aqueous extract of Asparagus cochinchinensis (Lour.) Merr. shoot in vivo and in vitro.MethodsA total of 80 Kun Ming mice were randomly divided into four groups (20/group). The mice in the control group received a daily subcutaneous injection of saline. A daily injection of D-galactose was administered to the aging model group, the vitamin C (Vc) group (positive control group), and the extract treatment group. Regular measurement of blood cells, nitric oxide synthase (NOS), catalase (CAT) activities, superoxide dismutase (SOD) activities, nitric oxide (NO), and malondialdehyde (MDA) concentration, and the expressions of NOS, SOD, and glutathione peroxidase (GPX) in serum levels were obtained. Furthermore, the microstructure of mice viscera was observed using hematoxylin and eosin staining.ResultsThe aqueous extract of A. cochinchinensis (Lour.) Merr. had similar 1,1-diphenyl-2-picrylhydrazyl radical 2,2-diphenyl-1-(2,4,6-trinitrophenyl) hydrazyl (DPPH·) [or 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS+)] and higher hydroxyl radicals (or superoxide anion; p < 0.05) radical scavenging capabilities to Vc. Moreover, compared with the aging model group, the aqueous extract of A. cochinchinensis (Lour.) Merr. shoot could obviously increase NOS, CAT, and SOD activities and the NO content, and reduce the MDA content (p < 0.05). Additionally, the microstructure of mice viscera was obviously improved and the expressions of NOS, SOD and GPX were also manifestly increased in the treatment group (p < 0.05).ConclusionThe aqueous extract of A. cochinchinensis (Lour.) Merr. shoot had a strong radical scavenging capability in vivo and in vitro, and might be used to diminish radicals in the body and consequently prevent aging

Organizational Ambidexterity Building via IT-enabled Strategic Learning and Business Learning: A Evolutionary Journey of Huawei

Organizations are commonly bothered by paradoxical pursuits, which make them demand on the development of organizational ambidexterity with dual exploitation and exploration abilities. This paper drawing on the organizational learning perspective, aims to uncover how the interaction of Information Technology (IT) and two distinguished organizational learning processes (i.e., strategic learning and business learning) dynamically contribute to the construction of organizational ambidexterity. To address this key research question, we studied an outstanding Chinese high-tech firm (Huawei) by revealing its evolutionary journey. We described how the IT-driven strategic learning leads to strategic transformation, while business learning results in the organizational stability in a certain period. Continuous exploration and exploitation constructed organizational ambidexterity. Specific strategic learning and business learning activities and methods were identified. This study not only fills the gap of the missing of IT artifacts in organizational learning and ambidexterity literatures but also offers valuable insights for other firms

Fiber based source of photon pairs at telecom band with high temporal coherence and brightness for quantum information processing

We experimentally demonstrate a bright pulsed source of correlated photon pairs at 1550 nm telecom band by pumping 300 m dispersion shifted fiber with a 4 ps pulse train. We investigate the coherence property of the source by measuring the second order intensity correlation function $g^{(2)}$ of individual signal (idler) photons. A preliminary Hong-Ou-Mandel type two-photon interference experiment with two such sources confirms the high temporal and spatial coherence of the source. The source is suitable for multi-photon quantum interference of independent sources, required in quantum information processing.Comment: 4 pages, 4 figures, submitte

A Coevolutionary Journey of Strategic Knowledge Management Alignment: A Chinese Case

Although knowledge has emerged as the strategic resource of the firm in the increasingly turbulent and dynamic environment, it is underestimated how knowledge management (KM) contributes to sustained competitive advantage of the firm over time. Drawing upon a coevolutionary view of alignment, this study examines a strategic KM coevolutionary mechanism in which KM strategy, processes, and infrastructure dynamically align with the changing competitive strategy; in turn, the KM derived competitive advantage drives the firm to pursue a more superior position in its niche. To trace the coevolutionary mechanism, we conducted a case study in Li-Ning Company, which experiences 20 years’ development and has become a leading sports goods company in China. Two strategic transitions result in the corresponding changes of its KM strategy, KM processes and infrastructure. The cumulated knowledge helps the firm upgrade from an imitator to a prospector with balanced performance portfolio. Theoretical and managerial implications are discussed

LEVERAGING E-GOVERNMENT FOR CITY TRANSFORMATION: A CASE STUDY OF DIGITAL WUYI

Seeing the scarcity of successful e-government programs in developing countries while a high failure rate reported on the opposite, this study investigates the success of \u27Digital Wuyi\u27 program in China. This study exhibits its ten-year roadmap in which the e-government has been continuously upgraded at a municipal level, spanning from e-government infrastructure and platform development, community informatization with rural priority, e-commerce development for pillar industry, to Internet of Things development. Further, this study identifies the key success factors and reflects the corresponding practices that lead Wuyishan City to achieve the success in e-government development. We find that sustainable and dynamic strategic planning, mayor\u27s leadership with entrepreneurships spirits and action learning, public-private partnership and modular promotion contribute much to the success of this municipal e-government project in China. Implications of this study can be derived for the municipal government development in China and other developing countries

Neuroglobin, a Novel Target for Endogenous Neuroprotection against Stroke and Neurodegenerative Disorders

Brain neurons and tissues respond to sublethal injury by activating endogenous protective pathways. Recently, following the failure of a large number of clinical trials for protective strategies against stroke that aim to inhibit a specific ischemia response pathway, endogenous neuroprotection has emerged as a more promising and hopeful strategy for development of therapeutics against stroke and neurodegenerative disorders. Neuroglobin (Ngb) is an oxygen-binding globin protein that is highly and specifically expressed in brain neurons. Accumulating evidence have clearly demonstrated that Ngb is an endogenous neuroprotective molecule against hypoxic/ischemic and oxidative stress-related insults in cultured neurons and animals, as well as neurodegenerative disorders such as Alzheimer’s disease, thus any pharmacological strategy that can up-regulate endogenous Ngb expression may lead to novel therapeutics against these brain disorders. In this review, we summarize recent studies about the biological function, regulation of gene expression, and neuroprotective mechanisms of Ngb. Furthermore, strategies for identification of chemical compounds that can up-regulate endogenous Ngb expression for neuroprotection against stroke and neurodegenerative disorders are discussed