Nanjing University of Information Science and Technology

About: Nanjing University of Information Science and Technology is a education organization based out in Nanjing, China. It is known for research contribution in the topics: Precipitation & Aerosol. The organization has 14129 authors who have published 17985 publications receiving 267578 citations. The organization is also known as: Nan Xin Da.

Achieving effective cloud search services: multi-keyword ranked search over encrypted cloud data supporting synonym query

Abstract: In recent years, consumer-centric cloud computing paradigm has emerged as the development of smart electronic devices combined with the emerging cloud computing technologies. A variety of cloud services are delivered to the consumers with the premise that an effective and efficient cloud search service is achieved. For consumers, they want to find the most relevant products or data, which is highly desirable in the "pay-as-you use" cloud computing paradigm. As sensitive data (such as photo albums, emails, personal health records, financial records, etc.) are encrypted before outsourcing to cloud, traditional keyword search techniques are useless. Meanwhile, existing search approaches over encrypted cloud data support only exact or fuzzy keyword search, but not semantics-based multi-keyword ranked search. Therefore, how to enable an effective searchable system with support of ranked search remains a very challenging problem. This paper proposes an effective approach to solve the problem of multi-keyword ranked search over encrypted cloud data supporting synonym queries. The main contribution of this paper is summarized in two aspects: multi-keyword ranked search to achieve more accurate search results and synonym-based search to support synonym queries. Extensive experiments on real-world dataset were performed to validate the approach, showing that the proposed solution is very effective and efficient for multikeyword ranked searching in a cloud environment.

Proton conducting oxides: A review of materials and applications for renewable energy conversion and storage

Abstract: Recent developments in proton conducting oxides (PCOs) present a promise of economic and sustainable energy conversion and storage devices such as protonic ceramic fuel cells, protonic ceramic electrolysis cells, gas purification, syn-gas membrane, and ammonia synthesis. This review provides a comprehensive overview of the development and recent trends in electrochemical cells based on the PCOs. Various protonic electrochemical cells are described here with basic working principles and critical parameters affecting the performance. Also, the electrochemical properties and recent progress on the PCO materials are reviewed and discussed. The overview of PCOs provides guidelines for the scientific-based rational design of PCO materials for the efficient protonic energy conversion and storage applications in academic and industrial fields.

Ocean Vector Winds Retrieval From C-Band Fully Polarimetric SAR Measurements

Abstract: We present an efficient algorithm for retrieving the ocean-surface wind vector from C-band Radar Satellite RADARSAT-2 fully polarimetric synthetic aperture radar (SAR) measurements based upon the copolarized geophysical model function, i.e., CMOD5.N, and the cross-polarized ocean backscatter model, i.e., C-2PO. The analysis of fine quad-polarization mode single-look complex SAR data and collocated in situ moored buoy observations reveals that the polarimetric correlation coefficient between co- and cross-polarization channels has odd symmetry with respect to the wind direction. This characteristic is different from the feature that normalized radar cross sections for quad-polarization have even symmetry regarding the wind direction. We first use the C-2PO model to directly retrieve wind speeds without any external wind-direction and radar-incidence-angle inputs. Subsequently, the retrieved wind speeds, along with incidence angles and CMOD5.N, are employed to invert the wind direction, still with ambiguities. The odd-symmetry property is then applied to remove the wind direction ambiguities. Thus, it is shown that fully polarimetric SAR measurements provide complementary directional information for the ocean-surface wind fields. This method has the potential to improve wind vector retrievals from space.

A Regional Ocean–Atmosphere Model for Eastern Pacific Climate: Toward Reducing Tropical Biases*

Abstract: The tropical Pacific Ocean is a climatically important region, home to El Nino and the Southern Oscillation. The simulation of its climate remains a challenge for global coupled ocean–atmosphere models, which suffer large biases especially in reproducing the observed meridional asymmetry across the equator in sea surface temperature (SST) and rainfall. A basin ocean general circulation model is coupled with a full-physics regional atmospheric model to study eastern Pacific climate processes. The regional ocean–atmosphere model (ROAM) reproduces salient features of eastern Pacific climate, including a northward-displaced intertropical convergence zone (ITCZ) collocated with a zonal band of high SST, a low-cloud deck in the southeastern tropical Pacific, the equatorial cold tongue, and its annual cycle. The simulated low-cloud deck experiences significant seasonal variations in vertical structure and cloudiness; cloud becomes decoupled and separated from the surface mixed layer by a stable layer in...