Identity-Based Encryption with Keyword Search from Lattice Assumption

Public key encryption scheme with keyword search （PEKS） enables us to search the encrypted data in a cloud server with a keyword, and no one can obtain any infor- mation about the encrypted data without the trapdoor corresponding to the keyword. The PEKS is useful to keep the management of large data storages secure such as those in a cloud. In this paper, to protect against quantum computer attacks, we present a lattice-based identity-based encryption scheme with key- word search. We have proved that our scheme can achieve ciphertext indistinguishability in the random oracle model, and our scheme can also achieve trapdoor security. In particular, our scheme can designate a unique tester to test and return the search results, therefore it does not need a secure channel. To the best of our knowledge, our scheme is the first iden- tity-based encryption scheme with keyword search from lattice assumption.

Spatial Data Process Using Python Script and Visual Programming Language in ArcGIS

Data are limitless. But those are usually not formed or created in our needs. Most of data providers deliver their data in Microsoft Excel spreadsheet, which is compatible with ArcGIS, the most widely used GIS （Geographic Information System） software in GIS sector. However, those table data contain much unnecessary information that do not need for a certain project. Using the raw data can increase processing times and reduce performance of geoprocessing tools. This study shows steps of how the raw data are being processed using ArcGIS ModelBuilder and Python script.

Mechanism of formation of low level jets in the South China Sea during spring and summer of 1998

The mechanism responsible for the formation of the low-level jet (LLJ) over the South China Sea during spring and summer of 1998 was analyzed through using the assimilated grid data provided by the South China Sea monsoon experiment (SCSMEX). More analyses were emphasized on a heavy rainfall process in the Zhujiang Delta area between 8th and 10th June 1998 in which a LLJ played a key role. Furthermore, the MM5 meso-scale model was utilized in studying the effects of the weather systems on the LLJ. The results showed that the kinetic energy associated with the LLJ transferred upward when the LLJ formed, which results in the fact that the big velocity of the LLJ expanded upward to higher level. Simulation verifies that a synoptic-scale low pressure in the low troposphere of the west of South China moved toward the east, with a low-troposphere synoptic-scale high pressure in the western Pacific moving toward the west. In this process, the approach of both systems leads to the reinforcement of pressure gradient force between them, making the kinetic energy needed by the formation of the LLJ increase. Through this process the LLJ formed and developed over the South China Sea between the low and high pressures. Because the formation of the LLJ indicates the enhancement of summer monsoon in the South China Sea, the mechanism responsible for formation of the LLJ could be used in explaining an enhancement of summer monsoon in the South China Sea.

Comparison between fully resolved and time-averaged simulations of particle cloud dispersion produced by a violent expiratory event

In this work we compare the DNS results(Fabregat et al.2021,Fabregat et al.2021)for a mild cough already reported in the literarure with those obtained with a compressible URANS equations with a k-ϵturbulence model.In both cases,the dispersed phase has been modelled as spherical Lagrangian particles using the one-way coupling assumption.Overall,the URANS model is capable of reproducing the observed tendency of light particles under 64µm in diameter to rise due to the action of the drag exerted by the buoyant puff generated by the cough.Both DNS and URANS found that particles above 64µm will tend to describe parabolic trajectories under the action of gravitational forces.Grid independence analysis allows to qualify the impact of increasing mesh resolution on the particle cloud statistics as flow evolves.Results suggest that the k-ϵmodel overpredicts the horizontal displacement of the particles smaller than 64µm while the opposite occurs for the particles larger than 64µm.