Similarity search or nearest neighbor search is a task of retrieving a set of vectors in the (vector) database that are most similar to the provided query vector. It has been a key kernel for many applications for a long time. However, it is becoming especially more important in recent days as modern neural networks and machine learning models represent the semantics of images, videos, and documents as high-dimensional vectors called embeddings. Finding a set of similar embeddings for the provided query embedding is now the critical operation for modern recommender systems and semantic search engines. Since exhaustively searching for the most similar vectors out of billion vectors is such a prohibitive task, approximate nearest neighbor search (ANNS) is often utilized in many real-world use cases. Unfortunately, we find that utilizing the server-class CPUs and GPUs for the ANNS task leads to suboptimal performance and energy efficiency. To address such limitations, we propose a specialized architecture named ANNA (Approximate Nearest Neighbor search Accelerator), which is compatible with state-of-the-art ANNS algorithms such as Google ScaNN and Facebook Faiss. By combining the benefits of a specialized dataflow pipeline and efficient data reuse, ANNA achieves multiple orders of magnitude higher energy efficiency, 2.3-61.6× higher throughput, and 4.3-82.1× lower latency than the conventional CPU or GPU for both million- and billion-scale datasets.

The purpose of this study is to optimize the composition of CSA (calcium sulfoaluminate) cement with sodium silicate (Na₂SiO₃) and gypsum for binder jetting 3D printing. The preliminary test was carried out with an applicator to decide the proper thickness of one layer before using the 3D printer. A liquid binder was then selected to maintain the shape of the particles. Based on the results, the optimal mixture of dry materials and a liquid activator was derived through various parametric studies. For dry materials, the optimum composition of CSA cement, gypsum, and sand was suggested, and the liquid activator made with sodium silicate solution and VMA (viscosity modified agent) were selected. The setting time with gypsum and sodium silicate was controlled within 30 s. In case of the delayed setting time and the rapid setting mixture, the jetting line was printed thicker or thinner and the accuracy of the printout was degraded. In order to adjust the viscosity of the liquid activator, 10% of the VMA was used in 35% of sodium silicate solution and the viscosity of 200–400 cP was suitable to be sprayed from the nozzle. With this optimal mixture, a prototype of atypical decorative wall was printed, and the compressive strength was measured at about 7 MPa.

The 26th International Display Workshops (IDW '19),Effect of Concentration of the Guest Dichroic Dye in Guest-Host Liquid Crystal Panel for Viewing Angle Controller of Display