Thin clients

The second type is the WAN (wide area network) installation. In this setup the LIMS take advantage of telecommunication technology to cover a great distance. The setup can also be used to connect disparate LANs together. In this configuration, the LIMS are installed on both the clients and a central server. The third type is the so-called centrally hosted thin client installation . For this setup, system administration is managed at a corporate center, where the LIMS are hosted and distributed via a WAN or the Internet with a virtual private network (VPN). The last and also the newest type is the ASP (Application Service Provision provider)-hosted installation. In this setup, the LIMS are hosted on a centrally managed server form and maintained by third-party specialists. Users access the LIMS with any Internet-connected PC with a standard Web browser. 

KolovaT, YounesN. Pat-Client web-enabled remote data management systems an alternative to Thin-Client web data entry. Controlled Clin Trials 2004 P49. 

In our view, architecture is not only about Gothic-scale structures but is also about all structures and relationships used down to the level of code.1 The decision to use a four-tier structure, with a thin client, a Web server, a business application server, and a database, is architectural. But, in the extreme, we consider a consistent use of getXQ and setX(x) methods also to be part of the (detailed) architecture. This view leads to a somewhat less formal definition of architecture. 

One other significant benefit of this technology worth mentioning is its ability to provide Web access to key applications. The Citrix MetaFrame product is a thin-client software product that extends the capabilities of server-based computing. It creates a client in the form of a Microsoft Active X control, allowing its nsers to run their Windows applications from within a standard web browser like Internet Explorer or Netscape. 

A three-tiered architecture includes one more node between the client and the database server—the middle tier. In a three-tiered architecture, business logic is offloaded from the client and the database server nodes to the middle tier. In fact, you can choose to further distribute the business logic among more than one middle tier node and still call it a three-tiered (or K-tiered) architecture because the idea is similar. Note that the tiers do not have to be physically separated. You can have both the middle tier server and the database server collocated on the same physical computer but running in different processes with separate memory spaces. Modem hardware architecture can partition a single hardware box into multiple virtually separate computers or domains. Typically, a three-tiered architecture supports a Web-based thin client although it can also work with a rich client. 

If a Web-based thin client is used, there is no client deployment needed. The updated system is deployed to the middleware only, and the clients can access it easily with a URL from a Web browser. 

From the top, the client layer resides on an end user s desktop, laptop, or handheld device, which is typically, but not limited to, a Windows PC with a Web browser. Usually a Web-based client layer is called thin client, which is lightweight. The programs that run inside the browser are typically JavaScript, VB Script, Java Applets, ActiveX, or Web browser plug-in. Using a rich client such as. NET or Java Swing is another choice, although this book focuses on a Web-based architecture. 

Top managers often think IT infrastructure is the machines and cables in the basement. They are wrong. IT infrastructure has become a complex system that drives IT performance and accounts for over half of the IT budget (Fig. 23.3). On top of that is the complexity of assimilating innovations such as voice-over-IP, thin clients, IT security standards, blade servers, or Linux at a near-breakneck pace. 

The web clients are often called thin clients in the enterprise application, because they do not directly query databases, execute complex business logic, or connect to legacy applications. Such heavyweight operations are off-loaded to the components in the web tier or business tier underneath in order to utilize the security, speed, service, and reliability provided by J2EE server-side technologies. The thin-client design makes the enterprise application scalable, and the development process simple and flexible. 

Adopting a thin client computing architecture concentrates recovery processes on a few key servers, thus reducing overall workload and numbers of personnel involved. 

Java, software vendors are starting to provide solutions featuring thin client software or web browsers as their front end. These solutions draw their application services from centralized servers instead of megabytes of software installed on the desktop. Since they utilize the Web as a transport medium, they are much easier to integrate with the outside world. They can also support nondesktop PC devices such as handheld PDAs. 

Networks are so fast nowadays that 3D volume rendering can be distributed from a central powerful computer to simple (and thus low cost) viewing stations, called thin clients (a.o. Terarecon Aquarius, Fig. 9.2). A powerful dedicated graphics board (in this case the VolumePro 1000) with dedicated hardware runs several 3D viewing applications simultaneously, and is remotely controlled by the... 

STATPack mobile was designed to be a thin-client application and when appropriate the existing code was used. By using the existing server code as much as possible, the development time was minimized and process consistency between the two systems was preserved. By extending the server code to the mobile platform, fhe developmenf feam was able to optimize their time and avoid introduction of new bugs or errors thaf would have required additional resources and time to fix. The functionalify for the STATPack mobile system was prioritized based on the previous information from the requirements ... 

In our project we customized the mobile app for BlackBerry devices because at that lime BlackBerry devices were restricted by the stale government approvals. The targeted user base does not currently have a wide variety of devices. The design still provides the possibility of using the application on other devices because of its thin-client architecture. 

The mobile thin client depends on the server when it comes to tasks that involve the CPU and tasks that are data intensive. The client is browser based and sends user requests to the server and displays the responses on the screen. By adopting this architecture, mobile thin clients do tend to be less powerful and are limited in the number of features they can provide. However, the advantage of running a mobile thin client is a lower cost of ownership, increased security, and a simpler architecture to maintain (Tang et al. 2011). 

Tang, W., J. H. Lee, B. Song, M. Islam, S. Na, and E. N. Huh, 2011, Multi-platform mobile thin client architecture in cloud environment. Procedia Environmental Sciences 11 499-504. 

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