Gokhan Gercek

Designing a Versatile Dedicated Computing Lab to Support Computer Network Courses: Insights from a Case Study

Introduction During the past two decades, the computing function within organizations has evolved from a support to a strategic function that can provide a competitive edge to an organization. As a result, the need for technology-savvy personnel has increased exponentially, and colleges and universities have expanded their CS, MIS and related programs to meet this personnel demand. This growth, in turn, has resulted in the need for more faculty and support resources (Barker, 1999; Cherry, Phillabaum & Valero, 2000; Madison, 2002). For many small US and international colleges and universities, introducing new computing programs and courses typically implies developing additional computing labs to support these programs. However, in developing these labs, the institutions normally encounter significant obstacles, such as budgetary constraints, lack of physical space to house the labs, conflicting computing support needs of different courses, and rapid obsolescence of technology (Borkowski, Elvove, Higgins & Kueppers, 2004; Jones, Tunc & Cherry, 2000; Lovgren, 2001; Madison, 2002; Walters, 1993; Wilson 2002). These obstacles become even more pronounced in the case of dedicated computing labs. A dedicated computer lab for a course is warranted when a general lab cannot provide adequate computing support for the course (Agarwal, Critcher, Foley, Santi & Sigle, 2001; Dubose, 2000; Hill, Carver, Humphries & Pooch, 2001). Conceptually, a dedicated lab is designed to support a specific course; normally, however, such labs support multiple courses (Belles, Gorka & Miller, 2002; Belles & Miller, 2002; Corbesro, 2003; Wooley, 2003). Consequently, it is imperative that the design and configuration of an under-development lab must be (1) versatile--to accommodate diverse and conflicting computing needs, (2) flexible--to efficiently support different courses, and (3) modular--to easily incorporate new technologies or allow lab reconfiguration (Giebel, 1999; Madison, 2002; Weeden, Scarborough & Bills, 2003; Wilson, 2002). The Management Information Systems (MIS) program at the University of Houston-Clear Lake (UHCL) has faced similar challenges since its inception in mid 1990s. Recently, the department developed a dedicated lab to support graduate and undergraduate courses such as computer networking, computer network security, host security, client-server system design, and system administration. During the lab design and development process, many choices were made to ensure versatility, flexibility and modularity of the lab to support multiple courses simultaneously. Drawing on their experiences in the design and development of this lab, the authors present a model of a computing lab to specifically support computer networking and related courses. This model presents both physical as well as logical layout design considerations. It is believed that this model will prove a helpful reference for institutions that are undertaking development of such new labs. Physical Layout of the Lab Figure 1 visually depicts the physical layout of the lab, and this section describes this layout in detail. The lab encompasses an approximately 2000 square foot area and is furnished with twenty-four desks each supporting one workstation, but capable of accommodating two separate workstations. With two seats per desk, the lab is capable of seating forty-eight students. The desks are arranged in a lecture-hall setting. At the rear side of the lab, racks are installed to house networking equipment and devices such as routers, firewalls, switches, hubs, a telephone switch (PBX) and patch panels. Another rack is utilized to house servers to be built by students. Ample space in the racks is provided for installing additional equipment as needed. The rack-based equipment is kept in the lab for students to perform hands-on experiments. There are two categories of server computers utilized in the lab. …

Securing Small Business Computer Networks: An Examination of Primary Security Threats and Their Solutions

Abstract This article addresses the primary threats to computer networks that a small business might encounter and also provides strategies to counter these threats. It emphasizes the key characteristics associated with each category of security threat and provides approaches to eliminate or alleviate these threats. The article also presents a case study of a small insurance company for which the authors helped design, implement and secure computer networks. This case study further clarifies the concepts and strategies presented in the paper.

Partitioning Real-Time Tasks With Replications on Multiprocessor Embedded Systems

Executing computing tasks with replications is an essential choice to achieve fault-tolerance in designing real-time, embedded systems. A problem of maximizing the number of real-time tasks with replications running on a multiprocessor embedded system is discussed in this letter. The partitioning problem can be modeled as a variant of the bin-packing problem. In the original problem, it is known that the first-fit (FF) method has a good worst-case performance bound of 4/3. Whether or not the same bound is achievable in the variant problem remains an open question. This letter closes the question by proving that the worst-case performance bound of using the FF method approaches to 2 but it never reaches it. Then, a tight bound of asymptotic worst-case performance is shown.

Approximation algorithms in partitioning real-time tasks with replications

Abstract Today is an era where multiprocessor technology plays a major role in designs of modern computer architecture. While multiprocessor systems offer extra computing power, it also opens a new range of opportunities to improve fault-robustness. This paper focuses on a problem of achieving fault-tolerance using replications in real-time, multiprocessor systems. In the problem, multiple replicas, or copies, of a computing task are executed on distinct processors to resist potential processor failures and computing faults. Two greedy, approximation heuristics, named Worst Fit Increasing K-Replication and First Fit Increasing K-Replication, are studied to maximise the number of real-time tasks assigned on a system with identical processors, respecting to the tasks’ replicating and timely requirements. Worst case performance is analysed by using an approximation ratio between the algorithms and an optimal solution. We mathematically prove that the ratios of using both algorithms are infinitely close to 2. Simulations are performed on a large set of testing cases which can be used to bring to light the average performance of using the algorithms in practice. The results show that both heuristic algorithms provide simple but fast and effective solutions to solve the problem. Graphical Abstract Assigning real-time tasks to a multiprocessor system with replications.

Significance of User Participation in a Hospital Information System Success: Insights From a Case Study

User participation in the development of a system is universally prescribed as an effective strategy to ensure the success of the resultant system. However, the existing literature on the merits of user participation only provides equivocal evidence. Various analyses of this literature point out that this equivocal evidence may be due to inconsistent operational measures of the user participation and system success constructs. Planned organizational change and participative decision making, the underlying paradigms of user participation construct, suggest that the development of some information systems may require blending of users’ system-related functional expertise and developers’ technical expertise to ensure system success. These paradigms also maintain that in case of well-defined, structured information systems user participation should enhance the likelihood of system success through better user understanding of the need for the system and system content and objectives, user trust, and a sense of system ownership. This research also described a case study involving the development and implementation of a medical records system for a neonatal intensive care unit in a large hospital in Texas. The case study provides evidence that in systems that require incorporation of user functional expertise user participation will enhance the likelihood of system success.