Limited (AECL) created the Therac-25 radiation therapy machine (Death and Denial). The major innovation of this machine is that it was much more computer-controlled than the previous machines of its kind. This enabled technicians to spend less time setting up the machine and more time working directly with patients. The reduced setup time also increased the number of patients that were able to be treated in one day (ComputingCases). Patients undergoing treatment from the Therac-25 are in communication
that the high-power electron beam was activated instead of the intended low power beam. This resulted in 100 times intended radiation being given to the patients. One of the victim of the machine was Ray, an accountant suffering from cancer. When Therac – 25 fired an intense radiation on him, he felt as if he was electrocuted. He
The Therac-25 Software Disaster The Therac-25 is a computerized medical radiation therapy machine for cancer patients. During the time span of June 1985 to January 1987, it was the source of six fatal or near fatal overdoses. These incidents were a result of a combination of factors that can be viewed as unethical actions made through the ranks of hierarchy, from the manufactures to the FDA. The Therac-25 is a medical dual-mode linear accelerator that is used to target the less sensitive cancer
Wide Area Networks The creation of wide area networks links mass communication from people all over the world with a vast variety of different uses. “A wide area network is telecommunications networks covering a large geographic area.” The internet is the biggest example of a wide area network and has influenced our daily lives all around the world. Wide area networks are connected to local area networks to enable computers to share, send, and access information on a larger scale. These recent
Introduction The purpose of this papers it to examine in detail the operation of one of the wide area network that we discussed in class. This paper discusses the difference between frame relay networks and other point to point networks, advantages, addressing schemes, and different protocols supported. The paper will explain virtual circuits briefly before moving to its other characteristics because they are the key to understanding frame relay concept in general. Other than virtual circuits, we
Asynchronous Transfer Mode (ATM) A Case Study Table of Contents: Introduction ………………………………… 3 Overview ………………………………… 3 Innovative Aspects ………………………………….. 5 Advantages …………………………………… 6 Disadvantages …………………………………… 6 Conclusion …………………………………… 7 Introduction:
Introduction When electronic devices transfer information to another electronic device, the devices need to know when data flow is beginning and ending. This is done with signals for synchronization.i This report will describe the two forms of data communications in terms of the physical interfaces and modes of operation. It will describe the features of data communications equipment in relation to synchronous and asynchronous communication including modems, network terminating units and sending
ASSIGNMENT # 1 In telecommunications, switching refers to the process in which digital electronics and computerized control are used to connect the circuits of the telephone for the purpose of making the telephone calls There are two types of switching 1. Packet Switching 2. Circuit Switching. Packet Switching: What is packet? Packets are the blocks or groups of data to be transmitted regardless of the data structure and data type. Methodology: In packet switching the data which is to be transmitted
Frame Relay and Leased Lines In networking there are many options in having data transferred from one location to another. Two of which include frame relay and leased lines. Frame relay is a communication method that transfers data by dividing information into packets and sending them over a virtual network. Frame relay is a difficult process to understand and to accomplish. Leased lines, however, is the permanent connection between two stations. Leased lines are simpler to understand and
Redefining The American Dream Consumption patterns portray the dynamic effect of the American Dream. The American Dream today is significantly different that it was fifty years ago. Today Americans work longer work hours, spend 40% more time watching T.V and 40% less time with their children (AGO 2001). “The avarice of mankind is insatiable,” claimed Aristotle when describing how the appetite of mankind is never satisfied (Durning). As every desire is satisfied a new one rises up to take its
Introduction A Wide Area Network is geographically dispersed telecommunication network. The term distinguishes a broader telecommunication structure from a local area network. Wide area network may be privately owned or rented, but the term usually connotes the inclusion of public network. An intermediate form of network in terms of geography is a metropolitan area network. WAN is communication network that are regional or worldwide in geographic area, with a minimum distance typical of that between
Introduction On 18 April 1942, while America was mired in combat and taking heavy losses throughout the Pacific, Lieutenant Colonel James "Jimmy" Doolittle lead eighty men from the 17th Bomb Group on a daring bombing raid into the heart of the Japanese capital city of Tokyo. These men, intent on avenging the Japanese attack on Pearl Harbor only months earlier, launched their airplanes off of a Navy Aircraft Carrier on its maiden voyage, the USS Hornet. Their mission was to destroy military targets
Mandatory Professional License for Software Designers Abstract: Given the wide impact and real-time safety concerns of some software applications, it seems reasonable to regulate who will be doing the writing of this critical software. A number of other professions dealing with human safety require their practitioners to be either licensed. At present software professionals are not licensed. However, because software does have far-reaching and potentially disastrous effects, all software
Ethics in Mission and Safety Critical Software Engineering “Engineering has a direct and vital impact on the quality of life for all people.” 1 It is by this premise that engineering codes of ethics have been written to outline professional standards for both managers and engineers. Exhibiting the highest standards of honesty and integrity are imperative for the protection of public health, safety, and welfare.2 When ethical principles are compromised, the risk of endangering others greatly
In 1987 the Food and Drug Administration (FDA) established its expectations regarding process validation in the Guidance for Industry Process Validation. In this document the general principles and process validation components that are considered vital towards effective process validation are outlined. It also highlights the importance that these approaches be consistently and repeatedly used by all manufacturers through their manufacturing processes. The FDA also outlines the importance of the
this illustrates the demands for software are high and rising. We have witnessed some immense changes in the industry ever since the “The Software Crisis” (1965-1985) where many problems in software development were identified. This included the Therac-25 incident and the aviation industry; which was plagued with software problems. Then came the 1985-1989 period where we manage to find solutions to the “Software Crisis”, by formalising methods, documentation and creating standards for software development
Why Software Systems Fail 1.0 IntroductionIn this report I will be concentrating on the failure of software systems. To understand why software systems fail we need to understand what are software systems. Software systems are a type of information system. This is because a software system is basically a means for hardware to process information. Flynn’s definition of an information system is:"An information system provides procedures to record and make available information, concerning part of