Multiprogramming And Time Sharing

Multiprogramming And Time Sharing In a multiprogramming and time sharing environment, several users share the system simultaneously. This situation can result in various security problems. What are two such problems? Ans1. (a) In Multiprogramming and time sharing environment multiple users share the data and system so these are following two problems which might occur There can be the case of pilfering of data, which can result in various problems. It means after gaining illegal access in somebody system and thieving the data is a problem One more problem can be, no proper accounting of resources, it means if somebody is using the resource without maintaining proper accounting data, is a serious problem. Can we ensure the same degree of security in a time shared machine as in a dedicated machine? Explain your answer. Ans1. (b) We cannot assure same level of security as it is presented in dedicated machine. Because in time sharing environment, multiple users are accessing the system, so it is somewhat difficult to implement because if we are planning to use a high-level encryption for the sharing environment, than it will be difficult to implement that security. Each and every security system made by human can be broken by another human. Under what circumstances would a user be better off using a time sharing system rather than a PC or single user workstation? Ans2. There are two types of basic working environments Time sharing environment Dedicated resource environment In time sharing environment, multiple users are sharing the system and resources and this type of environment is useful when the tasks which are to performed are big or large and hardware resources are fast efficient. The full power of the resources can be consumed for the user problems. Dedicated environment is useful when the tasks which are to be performed are small level. This environment is preferred when hardware resources are sufficient to handle the users problem. In the designing of the operating system there are two approaches modular kernel and layered approach? How are they different? Ans3. Both modular kernel and layered approach are the approaches of the designing of the architecture of operating system. Layered Approach: Layered approach follows the concept of design in the form of different layers. In this the operating system is divided into layers in which core layer is hardware resources and the topmost layer is User-Interface. The layers which are in-between interact with the layer below it and finish the tasks. In this all the subsystems are to be executed in strict order. Modular Kernel Approach: This approach divides the operating system designing into modules of various levels. Like for e.g. in modules various different fields like booting, process, jobs, etc are divided and they run their modules in random manner. In a single module a group of various tasks are specified. Difference between both these designs is that layered approach imposes strict ordering of other layers; lower layers are not allowed to invoke operations corresponding to upper layer operations, whereas in the case of modular approach various modules can invoke each other without any constraint. Part B There is guest operating system and a host operating system like VMware? List all the factors in choosing the host operating system? Ans4. The factors which affect the selection of host operating system are: The host operating system should be of upgraded version which you are using as using as guest operating system. Hardware resources get shared in case of guest operating system, so care must be taken off. Because if the resources scarcity occurs both the OS will hang. Operating system used must be stable. It more depends upon security and speed. The kernel is responsible for a action with the processes. Search through the action of kernel and describe what the action is? Ans5. Kernel is known as the heart of the Operating System. Kernel is the main task handler of the OS. It represents as a bridge between applications and the data processing which is performed at hardware level. The actions of Kernel are : Kernel sets up an address space for the program, loads the files containing the programs code into memory and executes it. Multi-tasking kernels are able to give the user the virtual view that the number of processes running simultaneously is higher than the maximum number of processes the computer is actually running. Kernel uses scheduling algorithms to determine which process is running next and how much time it will be given. The algorithm chosen may allow for some processes to have higher priority than others. The kernel generally also provides these processes a way to communicate; this is known as inter-process communication. Kernel is responsible for communicating the hardware resources with the software components. Co-operative multitasking, where each process is allowed to run uninterrupted until it makes a special request that tells the kernel it may switch to another process. Such requests are known as yielding. Q6. Considering both the system level and the programmer level. Consider the advantage and disadvantage of the following structure. Synchronous and asynchronous communication. Ans (a) Synchronous communication is direct communication. In which the communication is time synchronized. It means all the users are involved in the communication are present at the same time. Asynchronous communication does not require that all the users involved in the communication should be present at the same time. For e.g. e-mails, blogging. Asynchronous is useful when the communication is done at far scale means online. Automatic and explicit buffering. Ans (b) Automatic buffering provides a queue which of infinite length, which will never block the user while waiting to perform a task. Disadvantage: In this large amount of memory space is wasted while allocation. Explicit Buffering asks explicitly that how much memory must be allocated as the available queue. In this user can be blocked while it is performing some task Advantage: Less Memory space will be wasted with explicit buffering. Send by copy and send by reference Ans (c) Send by copy, in this type of method original value of the variable is never changed throughout the program or task. Whereas in the case of send by reference, address of the original variable is passed and any changes made in the reference value will be reflected in the original value. Fixed-sized and variable-sized messages. Ans (e) This concept is used at the time of allocation of space of the buffers. In fixed-sized, fix amount of memory is allocated to buffer which will create a problem at the time of memory allocation and forms a memory blockage. Because it can hold limited number of tasks/messages only. Whereas in variable sized the buffer memory can be reallocated and resized at any place. In this the buffer-size is not pre-known.

Flute Instrument

Well I choose Flute as my favorite instrument. But unfortunately it is nowhere mentioned that who actually discover Flute, but we have lot more information about the history of flute. Thousands of years ago it was found in the cave in Northern France with unknown number of holes. It was carved with bones. Those flutes were used during the hunting and magic rituals. As mentioned on the internet that the first flute which can be hold sideways was created in China.But before that Egyptians had flute. Though flute was made of bones but then we had wooden flutes, bamboo flutes. There were several ways to hold the flute you could hold left or right side and even hold it straight like a recorder. Flutes were played by hunters, shepherds, musicians in festive occasions and from the 13th century on also by soldiers. And these flutes are still played all over the world. After 1670 the flute became more poplar and was made of three pieces now.Famous Performers: There are several famous performe rs, but I pick only couple of them. Robert Aitken Flutist-Composer-Conductor http://www.robertaitkenflutist.com/Robert Aitken studied flute with Nicolas Fiore in Toronto and became principal flute of the Vancouver and was the youngest principal in that orchestra’s history. He studied electronic music with Myron Shaeffer and composition with John Weinzweig at University of Toronto and he served second flute of C.B.C Symphony Orchestra. He was one of the 12 instrumentalists invited by Pierre Boulez to present a solo recital at IRCAM (Paris) in 1977.He also taught flute during 1960-75 at University of Toronto, 1972-82 at the Shawnigan Summer School of the Arts (British Columbia) and in 1981 founded â€Å"Music at Shawnigan†, He used to conduct new music concerts and in 1987 he conducted the first performance of Schafer’s â€Å"Patria I† for the Canadian Opera Company. For that performance he got critical comment on his incredible variety of dynamics and timb res. Aitken is one of Canada’s outstanding composers. He also traveled in East Asia like  other composers and has been influenced by the contact non-Western musical cultures.Jeanne BaxtresserJeanne Baxtresser started playing flute at the age of nine and she was love with it. She plays as a solo flutist for 15 years at New York Philharmonic. She started her career at the age of 14 with Minnesota Orchestra. She started her professional career immediately after her graduation from Juilliard School. She was appointed as a principal Flute of the Toronto Symphony as was invited to New York Philharmonic by Music Director Zubin Mehta. She was a soloist player and for more than 50 occasions she has been featured as a soloist across North America and Europe. William Bennetthttp://www.williambennettflute.com/ http://www.williambennettflute.com/bio.htmlFamous composers:Robert Aitken Flutist-Composer-Conductor http://www.robertaitkenflutist.com/ As already mentioned above about Robert A itken. Johann Joachim Quantz (1697-1773)Flutist, composer, flute maker, teacher of Frederick the Great of Prussia, author of an influential method book on musical performance (1752). http://www.flutehistory.com/Players/Johann_Joachim_Quantz/index.php3 Quantz was one of the finest flute professional during 18th century. He has a proficiency to play all the instruments but he specializes in flute in 1719. He traveled mostly all over for his education but he then returned to Dresden. He spends most of his time in King of Prussia until his death where he composes, perform and make flute for king. Quantz have more than 300 collections of concertos and lots of sonatas, even some of them have never been published.As said that Quantz working for Frederick the Great and the flutes which were made by Quantz Frederick used to give those as a  gift to families and they are still preserved in the museums of Germany, the US, and the Japan. Because of his book his name was still remembered in 19 th century because of his association with Frederick the Great of Prussia, considered by many at that time as the founder of the German state.Famous Orchestras: http://www.gramophone.co.uk/editorial/the-world’s-greatest-orchestras http://www.philorch.orgAccording to report Philadelphia orchestra is considered one of the big ï ¬ ve American Orchestras. It was formed in 1990 by Fritz Scheelite. They perform at white house in 1906 it was an Exclusive concert. It looks so great that how these orchestras are formed with small groups to large groups. Whereas Gramophone, are one of the famous orchestras and presents world’s greatest orchestra. Few of them were Czech Philharmonic, Saito Kinen orchestra, Metropolitan opera orchestra.

How Steinbeck Presents the Character of Curley’s Wife in of Mice and Men? Essay

In the John Steinbeckà ¢s novel à ¢of Mice and Menà ¢ he introduces us to the character of Curleyà ¢s wife. She could be interpreted as a mis-fitting character in the novel as no one relates to her. Steinbeck relates her to how women were powerless during 1930à ¢s and makes her seem desperately lonely and isolated from the others on the ranch. She has sexual power which she uses to get to the men on the ranch and she just needs someone to talk to. She dislikes her husband and had a desire to become a movie star. She is not seem as an individual and has no name. This shows how a woman belonged to their husband. This essay is going to examine in detail how Curleyà ¢s wife has been presented in this novel. Steinbeck presents her as a negative married woman. She has been presented first through the dialogue of ranch-hand Candy when he describes her to George. His opinion is very sexist towards Curleyà ¢s wife as he says à ¢Curley married†¦a tartà ¢. This shows Steinbeck presents her in a very crude manner. The word à ¢tartà ¢ shows the immediate impression and effect Curleyà ¢s wife has on the other men on the ranch. Steinbeck used this effect because he wants to show the reader the first impression the man have about Curleyà ¢s wife. This affects the reader to pre-judge Curleyà ¢s wife even before she entered. She has been portrayed as dangerous. When Curleyà ¢s wife first appears both George and Lennie notices à ¢Ã¢â‚¬ ¦the rectangle of sunshine in the doorway is cut offà ¢. This suggests that Curleyà ¢s wife is like darkness. She is also dangerous and brings only trouble to ranch hands because when she appears their à ¢sunshineà ¢ is cut off. Light represents hope in this novel. The fact that light/sunshine has been cut off links back to the idea that Curleyà ¢s wife will stand between their dream and future and may take away their happiness and dream just like darkness. Steinbeck presents her as being very flirty and in need for attention. She is described as à ¢she has full rouged lips and wide spaced eyes and heavily made up. Her hair was hung in little rolled clusters, like sausagesà ¢. This part about her hair could be taken as an insult and she has failed to make herself attractive.

New Drugs For Breast Cancer Treatment Essay - 1382 Words

Novel chemotherapeutic agent: †¢ â€Å"Chemotherapeutic agents† are the drug which used to inhibit or kill microorganisms without affecting host body cells. Cancer chemotherapeutic agents New Drugs for Breast Cancer Treatment: 1. Herceptin: ïÆ' ¼ Type of drug: Monoclonal antibody A class of drugs developed to work alone or together with chemotherapy to seek out and attack specific cancer cells. ïÆ' ¼ Mechanism: Herceptin attaches itself to a protein called HER2 that is found on the surface of 20 to 25 percent of breast cancers. HER2 stimulates cell growth and prevents breast cancer cell death. When Herceptin binds to HER2 it can prevent the tumor from growing. 2.Taxotere and Taxol: ïÆ' ¼ Type of drug: chemotherapy agent. A class of drugs used to slow the growth of cancer or to kill cancer cells that have spread to other parts of the body. ïÆ' ¼ Mechanism: Taxotere prevents cancer cells from dividing. If cancer cells can’t divide, they can’t grow. 3.Raloxifene: ïÆ' ¼ Type of drug: Selective Estrogen Receptor Modulators (SERMs) ïÆ' ¼ Mechanism: Some breast cancers need estrogen to grow. Estrogen attaches to the breast cancer cells and promotes growth. When raloxifene is used, it blocks estrogen’s ability to promote tumor growth. 4. Xeloda: ïÆ' ¼ Type of drug: chemotherapy agent, A class of drugs used to slow the growth of cancer or to kill cancer cells that have spread to other parts of the body. ïÆ' ¼ Mechanism: This drug is changed by breast cancer cells into a chemotherapy drugShow MoreRelatedBreast Cancer Treatment1620 Words   |  7 PagesBreast Cancer Treatment Breast cancer is turning to be one of the top killer women in the world. This kind of cancerous tumor is attacking breast tissue of woman. A disease in which abnormal cells in the breast divide and multiply in an uncontrolled fashion. 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