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Topic Review
Virtual LAN
A virtual LAN (VLAN) is any broadcast domain that is partitioned and isolated in a computer network at the data link layer (OSI layer 2). LAN is the abbreviation for local area network and in this context virtual refers to a physical object recreated and altered by additional logic. VLANs work by applying tags to network frames and handling these tags in networking systems – creating the appearance and functionality of network traffic that is physically on a single network but acts as if it is split between separate networks. In this way, VLANs can keep network applications separate despite being connected to the same physical network, and without requiring multiple sets of cabling and networking devices to be deployed. VLANs allow network administrators to group hosts together even if the hosts are not directly connected to the same network switch. Because VLAN membership can be configured through software, this can greatly simplify network design and deployment. Without VLANs, grouping hosts according to their resource needs the labor of relocating nodes or rewiring data links. VLANs allow devices that must be kept separate to share the cabling of a physical network and yet be prevented from directly interacting with one another. This managed sharing yields gains in simplicity, security, traffic management, and economy. For example, a VLAN can be used to separate traffic within a business based on individual users or groups of users or their roles (e.g. network administrators), or based on traffic characteristics (e.g. low-priority traffic prevented from impinging on the rest of the network's functioning). Many Internet hosting services use VLANs to separate customers' private zones from one other, allowing each customer's servers to be grouped in a single network segment no matter where the individual servers are located in the data center. Some precautions are needed to prevent traffic "escaping" from a given VLAN, an exploit known as VLAN hopping. To subdivide a network into VLANs, one configures network equipment. Simpler equipment might partition only each physical port (if even that), in which case each VLAN runs over a dedicated network cable. More sophisticated devices can mark frames through VLAN tagging, so that a single interconnect (trunk) may be used to transport data for multiple VLANs. Since VLANs share bandwidth, a VLAN trunk can use link aggregation, quality-of-service prioritization, or both to route data efficiently.
  • 380
  • 09 Oct 2022
Topic Review
List of Alignment Visualization Software
This page is a subsection of the list of sequence alignment software. Multiple alignment visualization tools typically serve four purposes: The rest of this article is focused on only multiple global alignments of homologous proteins. The first two are a natural consequence of most representations of alignments and their annotation being human-unreadable and best portrayed in the familiar sequence row and alignment column format, of which examples are widespread in the literature. The third is necessary because algorithms for both multiple sequence alignment and structural alignment use heuristics which do not always perform perfectly. The fourth is a great example of how interactive graphical tools enable a worker involved in sequence analysis to conveniently execute a variety if different computational tools to explore an alignment's phylogenetic implications; or, to predict the structure and functional properties of a specific sequence, e.g., comparative modelling.
  • 380
  • 08 Nov 2022
Topic Review
Impacts of Surface Microchannels on Porous Fibrous Media
The microchannel increases the permeability of flow both in the directions parallel and vertical to the microchannel direction. The microchannel plays as the highway for the pass of reactants while the rest of the smaller pore size provides higher resistance for better catalyst support, and the propagation path in the network with microchannels is more even and predictable. 
  • 379
  • 21 Dec 2021
Topic Review
Sensor Network Environments
New technologies have driven the rise of what is being termed as the fourth industrial revolution. The introduction of this new revolution is amalgamating the cyber and physical worlds, bringing with it many benefits, such as the advent of industry 4.0, the internet of things, cloud technologies and smart homes and cities. These new and exciting areas are poised to have significant advantages for society; they can increase the efficiency of many systems and increase the quality of life of people. However, these emerging technologies can potentially have downsides, if used incorrectly or maliciously by bad entities. The rise of the widespread use of sensor networks to allow the mentioned systems to function has brought with it many security vulnerabilities that conventional “hard security” measures cannot mitigate. It is for this reason that a new “soft security” approach is being taken in conjunction with the conventional security means. Trust models offer an efficient way of mitigating the threats posed by malicious entities in networks that conventional security methods may not be able to combat. 
  • 379
  • 19 Aug 2022
Topic Review
Enterprise Client-server Backup
Enterprise client-server" backup software describes a class of software applications that back up data from a variety of client computers centrally to one or more server computers, with the particular needs of enterprises in mind. They may employ a scripted client–server backup model with a backup server program running on one computer, and with small-footprint client programs (referred to as "agents" in some applications) running on the other computer(s) being backed up—or alternatively as another process on the same computer as the backup server program. Enterprise-specific requirements include the need to back up large amounts of data on a systematic basis, to adhere to legal requirements for the maintenance and archiving of files and data, and to satisfy short-recovery-time objectives. To satisfy these requirements (which World Backup Day (31 March) highlights), it is typical for an enterprise to appoint a backup administrator—who is a part of office administration rather than of the IT staff and whose role is "being the keeper of the data". In a client-server backup application, the server program initiates the backup activity by the client program. This is distinct from a "personal" backup application such as Apple's Time Machine, in which "Time Machine runs on each Mac, independently of any other Macs, whether they're backing up to the same destination or a different one." If the backup server and client programs are running on separate computers, they are connected in either a single platform or a mixed platform network. The client-server backup model was originated when magnetic tape was the only financially-feasible storage medium for doing backups of multiple computers onto a single archive file;[note 1][note 2] because magnetic tape is a sequential access medium, it was imperative (barring "multiplexed backup") that the client computers be backed up one at a time—as initiated by the backup server program. What is described in the preceding paragraph is the "two-tier" configuration (in one application's diagram, the second-tier backup server program is named "server" preceded by the name of the application, and first-tier "agents" are backing up interactive server applications). That configuration controls the backup server program via either an integrated GUI or a separate Administration Console. In some client-server backup applications, a "three-tier" configuration splits off the backup and restore functions of the server program to run on what are called media servers—computers to which devices containing archive files are attached either locally or as Network-attached storage (NAS). In those applications, the decision on which media server a script is to run on is controlled using another program called either a master server or an optional central admin. server.
  • 379
  • 14 Oct 2022
Topic Review
Web Automated Human Interaction
Web Automated Human Interaction (Wahi) is a technology from Wahi Media, Inc. for simulating two-way conversation on the web. Conversations branch, based on the user's responses, and information about the audience is collected and reported in real time, allowing the wahi designer to hear and understand how viewers respond to the message.
  • 378
  • 19 Oct 2022
Topic Review
OpenJ9
Eclipse OpenJ9 (previously known as IBM J9) is a high performance, scalable, Java virtual machine (JVM) implementation that is fully compliant with the Java Virtual Machine Specification. OpenJ9 can be built from source, or can be used with prebuilt binaries available at the AdoptOpenJDK project for a number of platforms including Linux and Windows. OpenJ9 is also a core component of the IBM developer kit, which is embedded in many IBM middleware products, including WebSphere Application Server and Websphere Liberty. OpenJ9 is also a component of Open Liberty. Extensive configuration options ensure that the JVM can be tuned to satisfy the requirements of a wide range of Java applications, from complex enterprise applications that run on mainframe hardware to short-lived applications that run on container-based cloud services.
  • 378
  • 29 Nov 2022
Topic Review
IoT Sensor Systems Used for Monitoring Road Infrastructure
An intelligent transportation system is one of the fundamental goals of the smart city concept. The Internet of Things (IoT) concept is a basic instrument to digitalize and automatize the process in the intelligent transportation system. Digitalization via the IoT concept enables the automatic collection of data usable for management in the transportation system. The IoT concept includes a system of sensors, actuators, control units and computational distribution among the edge, fog and cloud layers. 
  • 378
  • 18 May 2023
Topic Review
The Rise of Adversarial Machine Learning
Internet of Things (IoT) technologies serve as a backbone of cutting-edge intelligent systems. Machine Learning (ML) paradigms have been adopted within IoT environments to exploit their capabilities to mine complex patterns. Despite the reported promising results, ML-based solutions exhibit several security vulnerabilities and threats. Specifically, Adversarial Machine Learning (AML) attacks can drastically impact the performance of ML models. It also represents a promising research field that typically promotes novel techniques to generate and/or defend against Adversarial Examples (AE) attacks.
  • 378
  • 29 May 2023
Topic Review
Critical Nodes in Temporal Networks
Many real-world systems can be expressed in temporal networks with nodes playing different roles in structure and function, and edges representing the relationships between nodes. Identifying critical nodes can help us control the spread of public opinions or epidemics, predict leading figures in academia, conduct advertisements for various commodities and so on. 
  • 378
  • 03 Jul 2023
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