El artículo describe someramente la técnica de la laca europea, contrastando la información extraída de la documentación histórica (material de archivo, de hemeroteca y tratadística), con los ...estudios directos y científicos efectuados en obras lacadas y con las publicaciones sobre la materia.
Nowadays, the volume of online data stored on websites is constantly increasing, and users’ demand for faster query response times is also on the rise with the expansion of network bandwidth. To ...improve the efficiency of database query, many large enterprises use database partitioning to divide huge database tables and speed up query results. While database partitioning methods based on query workloads have been successful, they have their limitations. These methods rely heavily on current workloads and the resulting partitioning structures may need to be improved when workloads change, a process called database repartitioning. Most current methods for repartitioning involve restarting the partitioning module directly, leading to significant overhead in industry due to the high complexity of the partitioning algorithm. Additionally, existing repartitioning models are often artificially determined and cannot achieve truly adaptive repartitioning. To address these issues, we propose a multi-tree training sampling model based on existing tree-shaped structure, which can speed up qdtree partitioning algorithm and reduce overhead caused by repartitioning. We also introduce improvements to qdtree structure to make it more adaptable to our method. For each query received by the partitioning model, we use a result-return rate mechanism to accumulate the evaluation of the current query on the partition structure, and initiate repartitioning only after a certain threshold is reached. Furthermore, we use the data redundancy storage technique to further improve query speed.
Edge computing constitutes a promising paradigm of managing and processing the massive amounts of data generated by Internet of Things (IoT) devices. Data and computation are moved closer to the ...client, thus enabling latency- and bandwidth-sensitive applications. However, the distributed and heterogeneous nature of the edge as well as its limited resource capabilities pose several challenges in implementing or choosing an efficient edge-enabled storage system. Therefore, it is imperative for the research community to contribute to the clarification of the purposes and highlight the advantages and disadvantages of various edge-enabled storage systems. This work aspires to contribute toward this direction by presenting a performance analysis of three different storage systems, namely MinIO, BigchainDB, and the IPFS. We selected these three systems as they have been proven to be valid candidates for edge computing infrastructures. In addition, as the three evaluated systems belong to different types of storage, we evaluated a wide range of storage systems, increasing the variability of the results. The performance evaluation is performed using a set of resource utilization and Quality of Service (QoS) metrics. Each storage system is deployed and installed on a Raspberry Pi (small single-board computers), which serves as an edge device, able to optimize the overall efficiency with minimum power and minimum cost. The experimental results revealed that MinIO has the best overall performance regarding query response times, RAM consumption, disk IO time, and transaction rate. The results presented in this paper are intended for researchers in the field of edge computing and database systems.
The High Pressure Die Casting (HPDC) process is characterized by a high degree of automation and therefore represents a data rich production technology. From concepts such as Industry 4.0 and the ...Internet of Production (IoP), it is well known that the utilization of process data can facilitate improvements in product quality and productivity. In this work, we present a concept and its first steps of implementation to enable data management via a data lake for HPDC. Our goal was to design a system capable of acquiring, transmitting and storing static as well as dynamic process variables. The measurements originate from multiple data sources based on the Open Platform Communication Unified Architecture (OPC UA) within the HPDC cell and are transmitted via a streaming pipeline implemented in Node-Red and Apache Kafka. The data are consecutively stored in a data lake for HPDC that is based on a MinIO object store. In initial tests the implemented system proved it to be reliable, flexible and scalable. On standard consumer hardware, data handling of several thousand measurements per minute is possible. The use of the visual programming language Node-Red enables swift reconfiguration and deployment of the data processing pipeline.
In this work, we explore opportunities to design shared storage systems that leverage the distance connectivity of NVMe over Fabrics (NVMe-oF). NVMe-oF enables the use of NVMe storage devices in a ...shared storage environment, where multiple servers can access the same storage device via RDMA. Leveraging the distance connectivity of NVMe-oF, we develop a shared file system called EXT4-oF by extending the EXT4 file system. EXT4-oF uses RDMA to enable a local file system to function as a shared file system without requiring remote daemon processes. EXT4-oF employs a novel NVMe-driven lazy cache coherence to maintain cache coherence of file system metadata across multiple compute nodes upon creating new files, all achieved without the need for any daemon processes. To ensure cache coherence, NVMe-driven lazy cache coherence mechanism requires compute nodes to perform a re-read of NVMe-oF to avoid false negative file open errors. Through our experiments, we demonstrate that EXT4-oF improves the performance of MinIO by minimizing network traffic between compute and storage nodes and eliminating the need for TCP/IP communication during remote reads.
Seasonal mortality of the citrusleafminer, Phyllocnistis citrellaStainton, was studied from 1994 through 1998 in`Tahiti' lime, Citrus aurantifolia (Christm.) Swingle,in Homestead, Florida. Survival ...of eachdevelopmental host stage and the proportionattacked by indigenous and introduced naturalenemies were determined. Before the recovery ofthe introduced parasitoid, Ageniaspiscitricola Logvinovskaya, in 1995, thethird-instar host had the highest averageproportion of parasitized individuals (0.14)followed by the prepupa (0.11) while the firstinstar had the lowest proportion parasitized(0.02). After the first recovery andestablishment of A. citricola, theproportion of pupae parasitized increased to0.56 followed by the prepupa (0.14) and thethird instar (0.11). Before the introduction ofA. citricola, the highest proportion ofhosts killed by predation was observed insecond instar (0.17) and third instar (0.15).After the establishment of the introducedspecies, the proportion of dead individuals dueto predation was greater for second instar(0.31) and third instar (0.21) larvae.Mortality caused by indigenous natural enemieswas significantly correlated with increases ofP. citrella density. Parasitism ofP. citrella by the exotic parasitoid,A. citricola, correlated less well to hostdensity over the season (r2 = 0.12) thandid mortality caused by indigenous naturalenemies (r2 = 0.76). Moreover, a higherpercent mortality in population of P. citrellawas obtained from predation by theindigenous natural enemies than the introducedparasitoid as shown in the mortality estimatesfrom 1995 to 1998.
Seasonal abundance and parasitism of the leafminer Phyllocnistis citrella Stainton were investigated from summer 1993 through spring 1995 on 'Tahiti' limes in Dade County, Florida. P citrella ...population density increased from spring through fall and declined during winter 1994 and 1995. Eight species of parasitoids attacked P. citrella immatures in commercial and experimental lime orchards. The Eulophid Pnigalio minio (Walker), a primary ectoparasitoid, comprised approximately 80% of the parasitoids that emerged from parasitized P. citrella. Species and abundance of adult parasitoids varied considerably between leafminer generations. Overall percentage of parasitism was higher on unsprayed than sprayed trees
Cirrospilus floridensis, reared from the citrus leafminer, Phyllocnistis citrella Staintain, is described and illustrated. Zagrammosoma zebralineatum De Santis and Pnigalio flavipes (Ashmead) are ...synonymized with Zagrammosoma multilineatum (Ashmead) and Pnigalio minio (Walker), respectively. /// Se describe e ilustra una nueva especie, Cirrospilus floridensis, criada a partir del minador de los cítricos, Phyllocnistis citrella Staintain. Se propone la sinonimia de Zagrammosoma zebralineatum De Santis con Zagrammosoma multilineatum (Ashmead) y de Pnigalio flavipes con (Ashmead) Pnigalio minio (Walker).
Provider: - Institution: - Data provided by Europeana Collections- Lettera di Boninsegna Matteo Di Lorenzo Di Matteo a Datini Francesco Di Marco e Comp., 10/08/1384, carte 1- All metadata published ...by Europeana are available free of restriction under the Creative Commons CC0 1.0 Universal Public Domain Dedication. However, Europeana requests that you actively acknowledge and give attribution to all metadata sources including Europeana
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