Server-based computing

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. 

Figure 1 Remote client-server-based computation of 3D coordinates from within a structure editor. The editor sends the atom types and connectivity information via RPC to a coordinate generation server because it is requested to write a 3D-format file. The server returns the 3D atomic coordinates, which are used by the editor to write the structure file...

Mainframes are large computers comprised of a cluster of tightly coupled machines or having multiple processors. These units will often be set up for specific applications as database servers, or for handling calculations such as those generated by quantum mechanics-based computational chemistry methods. 

In this chapter, we extend the one-dimensional MRTM transport and adsorption model (Zeng et al., 2002 Selim et al., 1990) to three-dimensional applications, using the altemating-direction-implicit (ADI) numerical algorithm to reduce computational complexity. We also discuss the development of a web-based system with a user-friendly interface providing client-side and server-side computing applications and web-based visualization functionality. The accuracy and efficiency issues of solution algorithms will be addressed in future publications. 

In addition to abstract searches, SciFinder Scholar allows browsing the table of contents for a group of journals and also citation linking. It should be noted that SciFinder Scholar is not web based but uses the client (local computerj/server (CAS computer) model, where the local library subscribes for such use. More information is available from the website [www.cas.org/SCIFINDER/SCHOLAR/index.html]. 

An OS/2-based computer that manages the software that is distributed to all the application s workstations. It takes care of communication between workstations and data base server. 

The server-based model is better than the peer-to-peer model for large networks (say 25 users or more) that need a more secure environment and centralized control. Server-based networks use a dedicated, centralized server. All administrative functions and resource sharing are performed from this point. This makes it easier to share resources, perform backups, and support an almost unlimited number of users. It also offers better security. However, it does need more hardware than that used by the typical workstation/server computer in a peer-to-peer resource model. Additionally, it requires specialized software (the NOS) to... 

MODEL Molecular Descriptor Lab (MODEL) (http //jing.cz3.nus.edu.sg/ cgi-bin/model/model.cgi) is a free Web-based server for computing a comprehensive set of 3778 molecular descriptors, which can be divided into 6 classes constitutional descriptors, electronic descriptors, physical chemistry properties, topological indexes, geometrical molecular descriptors, and quantum chemistry descriptors [73], Compounds can be provided to the server in various molecular formats such as PDB, MDL, MOL2, and COR, and the computed molecular descriptors are displayed in a few seconds or less. Cross-links to the relevant sections of the reference manual page are also provided for some of the descriptors and descriptor classes. 

Database Server UNIX -based computer with an Oracle database that manages "manufacturing" data (all data used at and coming from the shop floor and all specification data, such as bills of materials, specifications, batch records, etc.). 

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. 

Web-based systems offer several advantages over rich client easy to deploy and access, easy to scale (by adding more hardware resources to the application server), and shared computing resources (CPUs, memory, database connections). However, most of the information this book presents is not limited to Web-based applications. It promotes the loosely coupled Presentation Layer and Domain Layer so that business logic can be reused no matter what GUI technology is being used. 

The term computer system can define any of the following desktop systems client or of the following desktop systems client or server systems automated process control and laboratory systems host-based systems data acquisition and analysis systems and all associated software. The associated software comprises application software or firmware, system software, and computer system supporting documentation. ... 

A number of useful computational tools have been developed for predicting the identity of unknown proteins based on the physical and chemical properties of amino acids and vice versa. Many of these tools are available through the Expert Protein Analysis System (ExPASy) at http //www.expasy.ch (Appel et al., 1994) and other servers. 

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