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The Haiyang-1C (HY-1C) satellite was launched on September 7, 2018. The Chinese Ocean Color and Temperature Scanner (COCTS) onboard HY-1C has the capacity for ocean color and sea surface temperature (SST) observations. The sun glint reflected on sea surface can interfere with the radiance reaching the field of view of satellite sensor, leading to the higher reflectance that is misclassified as cloud and restrictions of satellite data availability. Due to the lack of ability to avoid sun glint, the bidirectional reflectance distribution function (BRDF) model is implemented in the sun glint correction of HY-1C/COCTS visible images. The atmospheric direct transmittance is calculated by aerosol optical depth (AOD) and Rayleigh optical depth (ROD). The comparisons before and after sun glint correction of visible images at different locations and different time are discussed and analyzed. The spectra are compared before and after the sun glint correction, and it has an obvious decrease in both radiance and reflectance. The performance of the BRDF model in low, moderate, and severe glint contaminations is compared. The results indicate that the BRDF model is useful in the sun glint correction of visible bands and leading to more HY-1C/COCTS clear-sky coverage, as consequence can be applied as the preprocessing in the cloud detection and SST retrieval to improve the clear-sky coverage. [ABSTRACT FROM AUTHOR]

The work by Harrison, Ruzzo, and Ullman (the HRU paper) on safety in the context of the access matrix model is widely considered to be foundational work in access control. In this paper, we address two errors we have discovered in the HRU paper. To our knowledge, these errors have not been previously reported in the literature. The first error regards a proof that shows that safety analysis for mono-operational HRU systems is in (\bf NP). The error stems from a faulty assumption that such systems are monotonic for the purpose of safety analysis. We present a corrected proof in this paper. The second error regards a mapping from one version of the safety problem to another that is presented in the HRU paper. We demonstrate that the mapping is not a reduction, and present a reduction that enables us to infer that the second version of safety introduced in the HRU paper is also undecidable for the HRU scheme. These errors lead us to ask whether the notion of safety as defined in the HRU paper is meaningful. We introduce other notions of safety that we argue have more intuitive appeal, and present the corresponding safety analysis results for the HRU scheme. [ABSTRACT FROM AUTHOR]

Several anonymization techniques, such as generalization and bucketization, have been designed for privacy preserving microdata publishing. Recent work has shown that generalization loses considerable amount of information, especially for high-dimensional data. Bucketization, on the other hand, does not prevent membership disclosure and does not apply for data that do not have a clear separation between quasi-identifying attributes and sensitive attributes. In this paper, we present a novel technique called slicing, which partitions the data both horizontally and vertically. We show that slicing preserves better data utility than generalization and can be used for membership disclosure protection. Another important advantage of slicing is that it can handle high-dimensional data. We show how slicing can be used for attribute disclosure protection and develop an efficient algorithm for computing the sliced data that obey the \ell-diversity requirement. Our workload experiments confirm that slicing preserves better utility than generalization and is more effective than bucketization in workloads involving the sensitive attribute. Our experiments also demonstrate that slicing can be used to prevent membership disclosure. [ABSTRACT FROM AUTHOR]

In practice, assigning access permissions to users must satisfy a variety of constraints motivated by business and security requirements. Here, we focus on Role-Based Access Control (RBAC) systems, in which access permissions are assigned to roles and roles are then assigned to users. User-role assignment is subject to role-based constraints, such as mutual exclusion constraints, prerequisite constraints, and role-cardinality constraints. Also, whether a user is qualified for a role depends on whether his/her qualification satisfies the role's requirements. In other words, a role can only be assigned to a certain set of qualified users. In this paper, we study fundamental problems related to access control constraints and user-role assignment, such as determining whether there are conflicts in a set of constraints, verifying whether a user-role assignment satisfies all constraints, and how to generate a valid user-role assignment for a system configuration. Computational complexity results and/or algorithms are given for the problems we consider. [ABSTRACT FROM PUBLISHER]

The authors propose an incentive-based access control (IBAC) that uses separate mechanisms for controlling aggregated risks and incentivizing users to reduce unnecessary risks. This mechanism encourages users to make necessary accesses while discouraging them from taking unnecessary risks. To achieve this, the authors introduce novel incentive mechanism based on contract theory. They demonstrate that Nash equilibriums can be achieved in which users' optimal strategy is performing the risk-mitigation efforts to minimize their organization's risk; the authors' human-subject studies empirically confirm these theoretical results. [ABSTRACT FROM PUBLISHER]