The Multilevel Structures of NURBs and NURBlets on Intervals

This dissertation is concerned with the problem of constructing biorthogonal wavelets based on non-uniform rational cubic B-Splines on intervals. We call non-uniform rational B-Splines ``NURBs , and such biorthogonal wavelets ``NURBlets . Constructing NURBlets is useful in designing and representing an arbitrary shape of an object in the industry, especially when exactness of the shape is critical such as the shape of an aircraft. As we know presently most popular wavelet models in the industry are approximated at boundaries. In this dissertation a new model is presented that is well suited for generating arbitrary shapes in the industry with mathematical exactness throughout intervals; it fulfills interpolation at boundaries as well

A brief review of hybrid skin-topological effect

The finding of non-Hermitian skin effect has revolutionized our understanding of non-Hermitian topological phases, where the usual bulk-boundary correspondence is broken and new topological phases specific to non-Hermitian system are uncovered. Hybrid skin-topological effect (HSTE) is a class of newly discovered non-Hermitian topological states that simultaneously supports skin-localized topological edge states and extended bulk states. Here we provide a brief review of HSTE, starting from different mechanics that have been used to realize HSTE, including non-reciprocal couplings, onsite gain/loss, and non-Euclidean lattice geometries. We also review some theoretical developments closely related to the HSTE, including the concept of higher-order non-Hermitian skin effect, parity-time symmetry engineering, and non-Hermitian chiral skin effect. Finally, we summarize recent experimental exploration of HSTE, including its realization in electric circuits systems, non-Hermitian photonic crystals, and active matter systems. We hope this review can make the concept of hybrid-skin effect clearer and inspire new finding of non-Hermitian topological states in higher dimensional systems.Comment: A review article with 13 pages and 9 figures. Comments are welcom

Facilitating Technology Transfer by Patent Knowledge Graph

Technologies are one of the most important driving forces of our societal development and realizing the value of technologies heavily depends on the transfer of technologies. Given the importance of technologies and technology transfer, an increasingly large amount of money has been invested to encourage technological innovation and technology transfer worldwide. However, while numerous innovative technologies are invented, most of them remain latent and un-transferred. The comprehension of technical documents and the identification of appropriate technologies for given needs are challenging problems in technology transfer due to information asymmetry and information overload problems. There is a lack of common knowledge base that can reveal the technical details of technical documents and assist with the identification of suitable technologies. To bridge this gap, this research proposes to construct knowledge graph for facilitating technology transfer. A case study is conducted to show the construction of a patent knowledge graph and to illustrate its benefit to finding relevant patents, the most common and important form of technologies

Thermal Performance and Moisture Accumulation of Mechanical Pipe Insulation Systems Operating at Below Ambient Temperature in Wet Conditions with Moisture Ingress

When pipes are used for chilled water, glycol brines, refrigerants, and other chilled fluids, energy must be spent to compensate for heat gains through the wall of the pipes. Higher fluid temperature at the point of use decreases the efficiency of the end-use heat exchangers and increases the parasitic energy consumption. Mechanical pipe insulation systems are often used to limit the heat gains and save energy in commercial buildings. Pipe insulation systems play an important role for the health of the occupied space. When a chilled pipe is uninsulated or inadequately insulated, condensation might occur and water will drip onto other building surfaces possibly causing mold growth. The critical issue with cold pipes is that the temperature difference between the pipe and its surrounding ambient air drives water vapor inside the insulation system and condensation commonly occurs when the water vapor comes in contact the chilled pipe surface. This paper experimentally studies this issue for pipe insulation systems operating at below ambient temperature. The moisture content and the associated thermal conductivity of several pipe insulation systems were measured under various wet condensing conditions with moisture ingress. Accelerated type tests in laboratory highlighted the propensity of moisture accumulation in the insulation systems with cylindrical configuration and with split longitudinal joints. The moisture accumulation rate was measured and the apparent thermal conductivity increased significantly in a 60 days period when water vapor entered a pipe insulation syste