The Therac 25 A case study in safety failure • Radiation therapy machine • “The most serious computer-related accidents to date” • People were killed • Reference: Nancy Leveson and Clark Turner‚ “The Investigation of the Therac-25 Accidents”‚ Computer‚ 26‚ 7 (July 1993) pp 18-41. Therac 25 Background • Medical linear accelerator developed by Atomic Energy of Canada‚ Ltd. in mid-1970s • Delivers 25 MeV photons or electrons of various energies • Controlled by PDP-11 minicomputer • Software
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Detailed Report on Manufacturing of 600 mw Stator Winding bar of Turbo Generator Submitted to: Mr. A.K. Dhiman Bhupesh Kumar Singh (B.TECH-III) AN ABSTRACT With increasing demands of per capita electrical consumption‚ the requirements of various power sources are also increasing at
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An Investigation of the Therac-25 Accidents -- Part III Nancy Leveson‚ University of Washington Clark S. Turner‚ University of California‚ Irvine Reprinted with permission‚ IEEE Computer‚ Vol. 26‚ No. 7‚ July 1993‚ pp. 18-41. Recall that the Tyler error occurred when the operator made an entry indicating the mode/energy‚ went to the command line‚ then moved the cursor up to change the mode/energy‚ and returned to the command line all within 8 seconds. Since the magnet setting takes about 8 seconds
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PERIOD 2: Organization and Reorganization of Human Societies‚ c. 600 BCE to c. 600 CE The Development and Codification of Religious and Cultural Traditions I. Codifications and further developments of existing religious traditions provided a bond among the people and an ethical code to live by. A. The association of monotheism with Judaism was further developed with the codification of the Hebrew Scriptures‚ which also reflected the influence of Mesopotamian cultural and legal traditions
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:::25 WAYS TO ENTER JANNAH::: 1. Whoever meets Allah without ascribing anything to Him will enter Jannah.[Bukhari] 2. Whoever believes (has Imaan) in Allah and His Messenger (sal Allahu alayhi wa sallam)‚ and establishes the prayer and fasts the month of Ramadan‚ it is incumbent upon Allah that He enters him in Jannah. [Bukhari] 3. Whoever builds a masjid seeking by it the Pleasure of Allah‚ Allah will build for him a similar place in Jannah. [Bukhari] 4. Whoever prays the two cool prayers
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Before 600 CE China changes from Warring States to an empire during the period of Qin and Han dynasty in efforts to unifying and consolidating China. There were similarities in their bureaucracy in the means of enforcing authority and have contributed in innovations on technology‚ but there were differences in political philosophy. Primarily‚ the Chinese states emerge 2200 BCE‚ under the Xia‚ Shang‚ and Zhou Dynasties‚ but fell into the age of warring states. Its unification had vanished and there
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Chapter 25: The World at War 1. Overview. Briefly describe Orson Wells’ broadcast. How did people respond and why? (Lecture) What is the significance of World War II for America’s political and economic history? 2. The Road to War. Describe the various American responses to the coming of World War II. How did FDR and Willkie’s differ in the 1940 election? What were the Lend-lease Act and the Atlantic Charter? 3. The Attack on Pearl Harbor. Why did the US avoid taking a
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1. The zodiac killer is definitely organized. He is able to hide his crime well considering they have not been caught. 2. The murderer has the ability to taunt the police with weird ciphers‚ phone calls‚ insulting and cryptic messages. All without being caught. 3. The Zodiac killer has a specific way he kills. One particular way that was performed a couple of times was him or her approaching people in cars and often couples. 4. The killer often times has bad handwriting and miss spells commonly
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AR 600–20 • 18 March 2008 5 Chapter 2 Command Policies 2–1. Chain of command a. The chain of command assists commanders at all levels to achieve their primary function of accomplishing the unit’s assigned mission while caring for personnel and property in their charge. A simple and direct chain of command facilitates the transmittal of orders from the highest to the lowest levels in a minimum of time and with the least chance of misinterpretation. The command channel extends upward in the
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APUSH/LEP Chapter 25 Questions – pgs. 865 – 887 1. Identify the three critics of New Deal and explain what their concerns were. 1. Huey P. Long. 2. Father Charles Coughlin 3. Dr. Francis Townsend 2. Explain the causes of labor violence in 1934? The textile industry‚ once concentrated in New England with outposts in New Jersey and Philadelphia‚ had started moving South in the 1880s. By 1933 Southern mills produced more than seventy percent of cotton and woolen textiles in more modern mills‚ drawing
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