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Efficiently re-identifying and tracking objects across a network of cameras is crucial for applications like traffic surveillance. Spatula is the state-of-the-art video database man- agement system (VDBMS) for processing RE-ID queries. However, it suffers from two limitations. Its spatio-temporal filtering scheme has limited accuracy on large camera networks due to localized camera history. It is not suitable for critical video analytics applications that require high recall due to lack of support for adaptive query processing. In this paper, we present TRACER, a novel VDBMS for efficiently processing RE-ID queries using an adaptive query pro- cessing framework. TRACER selects the optimal camera to process at each time step by training a recurrent network to model long- term historical correlations. To accelerate queries under a high recall constraint, TRACER incorporates a probabilistic adaptive search model that processes camera feeds in incremental search windows and dynamically updates the sampling probabilities using an exploration-exploitation strategy. To address the paucity of benchmarks for the RE-ID task due to privacy concerns, we present a novel synthetic benchmark for generating multi-camera RE-ID datasets based on real-world traffic distribution. Our evaluation shows that TRACER outperforms the state-of-the-art cross-camera analytics system by 3.9⇥ on average across diverse datasets. 

In this research study, the fracture strength of flat 10 mm thick annealed glass sheets having an abrasive water-jet cut surface and bearing against a transparent interface material is experimentally investigated. The transparent interface material is necessary to provide axial-compressive force continuity in modular compression-dominant all- glass shell structures. A series of short glass columns were tested in axial compression under a variety of load cases, which included cyclic, creep, and monotonic-to-fracture loading. A target glass fracture bearing stress of 36.6 MPa is identified and represents an upper bound bearing stress for annealed glass compression members failing in a flexural buckling mode. The study concludes the transparent thermoplastic material, known as Surlyn, was able to achieve a fracture strength that exceeds the target value and that the fracture strength is not affected by cyclic or creep loading. Consequently, column-related failure limit states will occur before glass fracture is associated with interface bearing. Glass fracture occurs in Type-I mode, reflecting the presence of interface tensile stress. Furthermore, the monotonic bearing stiffness in the service range of 5 to 15 MPa is increased by 20 % and 16 % for samples subjected to cyclic and creep loading, respectively, relative to monotonic-only samples. 

Multi-layer spatial structures usually take considerable external loads with a small material usage at all scales. Polyhedral graphic statics (PGS) provides a method to design multi-layer funicular polyhedral structures, and the structural forms are usually materialized as space frames. Our previous research shows that the intrinsic planarity of the polyhedral geometries can be harnessed for efficient fabrication and construction processes using flat-sheet materials. Sheet-based structures are advantageous over conventional space frame systems because sheets can provide more load paths and constrain the kinematic degrees of freedom of the nodes. Therefore, they are more capable of taking a wider variety of load cases compared to space frames. Moreover, sheet materials can be fabricated into complex shapes using CNC milling, laser cutting, water jet cutting, and CNC bending techniques. However, not all sheets are necessary as long as the load paths are preserved and the system does not have kinematic degrees of freedom. To find an efficient set of faces that satisfies the requirements, this paper first incorporates and adapts the matrix analysis method to calculate the kinematic degrees of freedom for sheet-based structures. Then, an iterative algorithm is devised to help find a reduced set of faces with zero kinematic degrees of freedom. To attest to the advantages of this method over bar-node construction, a comparative study is carried out using finite element analysis. The results show that, with the same material usage, the sheet-based system has improved performance than the framework system under a range of loading scenarios. 

Multi-layer spatial structures usually take considerable external loads with very limited material usage at all scales, and Polyhedral Graphic Statics (PGS) provides a method to design multi-layer funicular polyhedral structures. The structural forms usually materialized as space frames. Our previous research shows that the intrinsic planarity of the polyhedral geometries can be harnessed for efficient fabrication and construction processes using flat-sheet materials. Sheet-based structures are advantageous over the conventional space frame systems because sheets can provide more load paths and constrain the kinematic degrees of freedom of the nodes. Therefore, they can take a wider range of load compared to space frames. Moreover, sheet materials can be fabricated to complex shapes using CNC milling, laser cutting, water jet cutting, and CNC bending techniques. However, not all sheets are necessary as long as the load paths are preserved, and the system does not have kinematic degrees of freedom. To find a reduced set of faces that satisfies the requirements, this paper incorporates and adapts the matrix analysis method to calculate the kinematic degree of freedom of sheet-based structure. Built upon this, an iterative algorithm is devised to help find the reduced set of faces with zero kinematic degree of freedom. To attest the advantage of this method over bar-node construction, a comparative study is carried out using finite element analysis. The result shows that, with the same material usage, the sheet-based system has improved performance than the framework system under a wide range of loading scenarios.