Traffic-Reduction for High-Availability Seamless Redundancy (HSR) Protocol Using Dual Virtual Paths Algorithm

2013 ◽  
Author(s):  
Saad Allawi Nsaif ◽  
Jong Myung Rhee
Keyword(s):  
High Availability ◽  
Virtual Paths ◽  
Traffic Reduction

HALR: A TCP Enhancement Scheme Using Local Caching in High-Availability Cluster

2009 ◽  
Vol E92-B (1) ◽  
pp. 26-33
Author(s):  
Yi-Hsuan FENG ◽  
Nen-Fu HUANG ◽  
Yen-Min WU
Keyword(s):  
High Availability

Clustering Server Pada Cloud Computing Berbasis Proxmox VE Menggunakan Metode High Availability

2018 ◽  
Vol 3 (1) ◽  
Author(s):  
Linda Apriliana ◽  
Ucuk Darusala Darusalam ◽  
Novi Dian Nathasia
Keyword(s):  
Cloud Computing ◽  
File System ◽  
High Availability ◽  
Client Server ◽  
Network File System

Layanan dan data teknologi Cloud Computing tersimpan pada server, hal ini menjadikan faktor pentingnya server sebagai pendukung ketersediaan layanan. Semakin banyak pengguna yang mengakses layanan tersebut akan mengakibatkan beban kinerja mesin server menjadi lebih berat dan kurang optimal, karena layanan harus bekerja menyediakan data terus-menerus yang dapat diakses kapanpun oleh penggunanya melalui jaringan terkoneksi. Perangkat keras server memiliki masa performa kinerja. Hal serupa dengan perangkat lunak yang dapat mengalami crash. Dengan fungsi server yang memberikan layanan kepada client, server dituntut untuk memiliki tingkat availability yang tinggi. Hal tersebut memungkinkan mesin server mengalami down. Server juga harus dimatikan untuk keperluan pemeliharaan. Penelitian bertujuan ini membangun Clustering Server yang dapat bekerja bersama yang seolah merupakan sistem tunggal diatas lingkungan virtual. Hal ini merupakan solusi untuk mengatasi permasalahan tersebut. Pada penelitian ini penulis menggunakan server virtualisasi proxmox, FreeNAS sebagai server NAS dan DRBD untuk pendukung ketersediaan layanan tinggi dalam lingkup HA, sinkronisasi data dalam High Availability (HA) yang dapat melakukan mirroring sistem kemesin lain. Dengan diterapkannya metode HA dan sinkronasi DRBD serta penggunaan NFS (Network File System) pada sistem cluster didapatkan hasil rata-rata waktu migrasi sebesar 9.7(s) pada node1 menuju node2, 3.7(s) node2 menuju node3, dan 3(s) pada node3 menuju node1. Didaptkan juga waktu downtime yang lebih sedikit yaitu sebesar 0.58 ms pada node1, 0.02 ms pada node2, dan 0.02 ms pada node3.

scholarly journals The food web in a subterranean ecosystem is driven by intraguild predation

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Andrea Parimuchová ◽  
Lenka Petráková Dušátková ◽  
Ľubomír Kováč ◽  
Táňa Macháčková ◽  
Ondřej Slabý ◽  
...  
Keyword(s):  
Food Web ◽  
Trophic Interactions ◽  
Intraguild Predation ◽  
Linear Models ◽  
Niche Overlap ◽  
Trophic Niche ◽  
High Availability ◽  
Large Prey ◽  
Arthropod Predators ◽  
Body Sizes

AbstractTrophic interactions of cave arthropods have been understudied. We used molecular methods (NGS) to decipher the food web in the subterranean ecosystem of the Ardovská Cave (Western Carpathians, Slovakia). We collected five arthropod predators of the species Parasitus loricatus (gamasid mites), Eukoenenia spelaea (palpigrades), Quedius mesomelinus (beetles), and Porrhomma profundum and Centromerus cavernarum (both spiders) and prey belonging to several orders. Various arthropod orders were exploited as prey, and trophic interactions differed among the predators. Linear models were used to compare absolute and relative prey body sizes among the predators. Quedius exploited relatively small prey, while Eukoenenia and Parasitus fed on relatively large prey. Exploitation of eggs or cadavers is discussed. In contrast to previous studies, Eukoenenia was found to be carnivorous. A high proportion of intraguild predation was found in all predators. Intraspecific consumption (most likely cannibalism) was detected only in mites and beetles. Using Pianka’s index, the highest trophic niche overlaps were found between Porrhomma and Parasitus and between Centromerus and Eukoenenia, while the lowest niche overlap was found between Parasitus and Quedius. Contrary to what we expected, the high availability of Diptera and Isopoda as a potential prey in the studied system was not corroborated. Our work demonstrates that intraguild diet plays an important role in predators occupying subterranean ecosystems.

scholarly journals Sources of Nitrogen for Winter Triticale (Triticosecale Wittm. ex A.Camus) Succeeding Pea (Pisum sativum L.)

Agronomy ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 527
Author(s):  
Andrzej Wysokinski ◽  
Izabela Lozak ◽  
Beata Kuziemska
Keyword(s):  
Root Nodule ◽  
Crop Residues ◽  
Spring Barley ◽  
Sandy Soils ◽  
High Availability ◽  
Atmospheric Nitrogen ◽  
15N Isotope ◽  
Carbon And Nitrogen ◽  
Winter Triticale ◽  
Pisum Sativum L

Atmospheric nitrogen biologically reduced in legumes root nodule and accumulated in their postharvest residues may be of great importance as a source of this macronutrient for succeeding crops. The aim of the study was to determine nitrogen uptake by winter triticale from pea postharvest residues, including N fixed from atmosphere, using in the study fertilizer enriched with the 15N isotope. Triticale was grown without nitrogen fertilization at sites where the forecrops had been two pea cultivars (multi-purpose and field pea) and, for comparison, spring barley. The triticale crop succeeding pea took up more nitrogen from the soil (59.1%) and less from the residues of the forecrop (41.1%). The corresponding values where the forecrop was barley were 92.1% and 7.9%. In the triticale, the percentage of nitrogen derived from the atmosphere, introduced into the soil with pea crop residues amounted to 23.8%. The amounts of nitrogen derived from all sources in the entire biomass of triticale plants grown after harvesting of pea were similar for both pea cultivars. The cereal took up more nitrogen from all sources, when the soil on which the experiment was conducted had higher content of carbon and nitrogen and a greater amount of N was introduced with the pea residues. Nitrogen from pea residues had high availability for winter triticale as a succeeding crop cultivated on sandy soils.

scholarly journals A Navigation and Augmented Reality System for Visually Impaired People

Sensors ◽  
2021 ◽  
Vol 21 (9) ◽  
pp. 3061
Author(s):  
Alice Lo Valvo ◽  
Daniele Croce ◽  
Domenico Garlisi ◽  
Fabrizio Giuliano ◽  
Laura Giarré ◽  
...  
Keyword(s):  
Augmented Reality ◽  
Visually Impaired ◽  
Virtual Path ◽  
Physical Support ◽  
Augmented Reality System ◽  
Virtual Paths ◽  
Visually Impaired People ◽  
Impaired People ◽  
Autonomous Mobility ◽  
Indoor And Outdoor

In recent years, we have assisted with an impressive advance in augmented reality systems and computer vision algorithms, based on image processing and artificial intelligence. Thanks to these technologies, mainstream smartphones are able to estimate their own motion in 3D space with high accuracy. In this paper, we exploit such technologies to support the autonomous mobility of people with visual disabilities, identifying pre-defined virtual paths and providing context information, reducing the distance between the digital and real worlds. In particular, we present ARIANNA+, an extension of ARIANNA, a system explicitly designed for visually impaired people for indoor and outdoor localization and navigation. While ARIANNA is based on the assumption that landmarks, such as QR codes, and physical paths (composed of colored tapes, painted lines, or tactile pavings) are deployed in the environment and recognized by the camera of a common smartphone, ARIANNA+ eliminates the need for any physical support thanks to the ARKit library, which we exploit to build a completely virtual path. Moreover, ARIANNA+ adds the possibility for the users to have enhanced interactions with the surrounding environment, through convolutional neural networks (CNNs) trained to recognize objects or buildings and enabling the possibility of accessing contents associated with them. By using a common smartphone as a mediation instrument with the environment, ARIANNA+ leverages augmented reality and machine learning for enhancing physical accessibility. The proposed system allows visually impaired people to easily navigate in indoor and outdoor scenarios simply by loading a previously recorded virtual path and providing automatic guidance along the route, through haptic, speech, and sound feedback.

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