Explain the Purpose of an Operating System Essays

Explain the Purpose of an Operating System Essays Explain the Purpose of an Operating System Essay Explain the Purpose of an Operating System Essay Explain the purpose of an operating system Process Management A multitasking operating system may give the appearance that a lot of processes are running concurrently/simultaneously, this is not true as only one process can be executing at any one time on a single-core CPU, unless on a multi-core or similar technology. Processes are often called tasks in embedded operating systems. The function of the task or process is something that takes up time, as opposed to memory, which is something that takes up space or capacity For security and reliability reasons most modern operating systems prevent direct communication between independent processes, providing strictly mediated and controlled inter-process communication functionality. Memory Management This involves providing ways to allocate portions of memory to programs at their request, and freeing it for reuse when no longer needed. The management of main memory is critical to the computer system. Virtual memory systems separate the memory addresses used by a process from actual physical addresses, allowing separation of processes and increasing the effectively available amount of RAM using paging or swapping to secondary storage. The quality of the virtual memory manager can have a big impact on overall system performance. Processes should not be able to source the memory for another process without permission. This is called memory protection, and prevents malicious or malfunctioning code in one program from interfering with the operation of other running programs. Disk Management Basic storage involves dividing a disk into primary and extended partitions. This is the way that all versions of Windows that were reliant on DOS-handled storage took, and disks formatted in this manner are known as basic disks. Dynamic storage involves the use of a single partition that covers the entire disk, and the disk itself is divided into volumes or combined with other disks to form volumes that are greater in size than one disk itself. Volumes can use any supported file system. Networking Networking is a collection of hardware components and computers interconnected by communication channels eg. Ethernet, that allows sharing of resources and information. -Using a network, people can communicate efficiently and easily via e-mail, instant messaging, chat rooms, telephony, video telephone calls, and videoconferencing. -In a networked environment, each computer on a network can access and use hardware on the network. Suppose several personal computers on a network each require the use of a printer. If the personal computers and a laser printer are connected to a network, each user can then access the laser printer on the network, as they need it. -In a network environment, any authorized user can access data and information stored on other computers on the network. The capability of providing access to data and information on shared storage devices is an important feature of many networks. -Users connected to a network can access application on the network. Security The on-going and excessive practice of protection for the confidentiality and honesty of information and system resources so that an unauthorized user has to spend an unacceptable amount of time or money or absorb too much risk in order to defeat it, with the ultimate goal that the system can be trusted with sensitive information. Other It provides a very stable and rigid way for apps to deal with the hardware without having to know everything about it. But not anyone person can know everything about it as it’s too large and has to be built piece by piece. The most important program that runs on a computer. Every computer used day to day use will need an operating system to operate other programs. Operating systems perform basic tasks, such as recognizing input from the keyboard, and sending output to the screen, keeping track of files on the disk, and controlling peripheral devices such as disk drives and printers. All if not most of the OS’s use TCP/IP networking protocols this mean they can network to other computers and use printers or scanners and other peripherals. For large systems, the operating system has even greater responsibilities and powers. It makes sure that different program are able to run with each other and don’t interfere. The operating system is also responsible for security, making sure that the computer and the files are protected from unauthorised users. Newer file systems use a very simple yet can be very large. The files are distributed into directories, like a hierarchy, a folder in folder. FAT12, FAT16, FAT32, NTFS, ExFAT and ZFS are all file systems. Operating systems can be classified as follows: -multi-user: Allows two or more users to run programs at the same time. Some operating systems allow hundreds or even thousands of users. -multiprocessing: Supports running a program on more than one CPU. -multitasking: Allows more than one program to run at the same time. -multithreading: Allows different parts of a single program to run at the same time. -real time: Responds to input instantly. General-purpose operating systems, such as DOS and UNIX, are not real-time. Operating systems provide a software platform on top of which other programs, called application programs, can run. The application programs must be written to run on top of a particular operating system. Your choice of operating system, therefore, determines to a great extent the applications you can run. For PCs, the most popular operating systems are Windows in which 90% of the world use, but others are available, such as Linux. Security can be in two forms internal and external, internal is already running in the background of the computer and will protect from programs isabling the antivirus and installing spyware. External is like passwords and firewalls that protect your computer files from outside in intrusions. The OS performs most of the functions that the user wants it is the most complex program on the computer. If it’s down nothing can run and recovery from errors become critical. As a user, you normally interact with the operating system through a set of commands . For example, the DOS operating system contains commands for copying files and changing the names of files, respectively. The commands are accepted and executed by a part of the operating system called the command processor or command line interpreter. Graphical user interfaces (GUI) allow you to enter commands by pointing and clicking at objects that appear on the screen. Problems occur like it crashes or it’s to slow these are unsolved and are never perfect for any use as it doesn’t do everything it was designed to do. Don’t adapt or change very easily and can also become a problem for some users.

Life Experiences of the Elderly Patients with Diabetes Mellitus Research Paper

Life Experiences of the Elderly Patients with Diabetes Mellitus - Research Paper Example According to the most recent forecasts, the number of patients with different types of diabetes will reach more than 360 million globally by 2030 (Wild, Roglic, Green, Sicree, and King, 2004). The lion's share of such occurrence is attributed to the elderly population. Most likely, the main reason for high vulnerability of the elderly population to diabetes is the ageing process that leads to a broad range of physiological changes, including decreased or deteriorated functionality of vital life organs (Rother, 2007). A number of studies have been conducted up to date to explore the effects of diabetes on the general health condition of the elderly patients. However, only few works are available to investigate specific life experiences of the elderly patients with diabetes though such research is necessary to improve the quality of health care for the elderly. Various types of diabetes and chronic illnesses associated with late adulthood represent a serious challenge for modern health care practitioners. According the estimates provided by the National Academy on an Aging Society (NAAS) and APA almost 4/5 of the elder adult population suffers from at least one chronic illness, while majority of seniors have multiple chronic health problems the most common of which are arthritis, hypertension, hearing impairments, heart disease, cataracts, various types of diabetes, osteoporosis, vascular diseases, neurological diseases, including stroke, and respiratory diseases (APA, 2003). Absolute majority of these illnesses and health problems are associated with specific life experiences, psychological issues and mental health problems, which should be taken into consideration during treatment (Frazer, Leicht, & Baker, 1996). Understanding of specific life experiences of senior diabetic patients is highly essential in the clinical setting for several reasons. Firstly, it will enable the health practitioner to design a correct treatment strategy to cope with the disease and improve quality of the patient's life. Secondly, such understanding is likely to contribute greatly to the efficiency of non-clinical (social) support of the diabetic patients and decrease the occurrence of complications, such as, for example, hypoglycemic episodes. This study employs phenomenological approach to investigate the specific life experiences and meaning of life of senior patients with diabetes. Literature review There is sufficient literature addressing various aspect of diabetes and particularly its relationship with the quality of patient's life. The following review briefly describes several most notable publications that provide valuable background information in the context of this study. One of the most recent studies carried out by Peck (2003) establishes a link between several chronic illnesses including type 2 diabetes in the elderly population and quality of life. The concept of 'quality of life' covers a number of different aspects such as food preferences, level of physical activity, psychological issues and social status, etc. Besides, the author provides some credible evidence that ability of the elderly diabetic patients to effectively cope with the illness normally results in substantially improved qualify of

An Anomaly Detection Scheme for prevention of collaborative attacks Dissertation

An Anomaly Detection Scheme for prevention of collaborative attacks - Dissertation Example These systems can be networks, ISP core or P2P systems. Some of the attackers that can collaborate to paralyze a system include, Denial of Messages attacks in which corrupt nodes interfere with radio signals of the genuine nodes thus preventing them from receiving messages. Secondly, Sybil attacks in which users acquire multiple fake identities, controls various nodes of the system, and eventually controls its decisions. Finally malicious flooding where a malicious node floods the system with messages. These attackers have various characteristics that lead to inefficiency of a system. They can cause disruptions at short intervals making the system very slow to respond to any action or they can concentrate at various nodes to cause confusion to the anomaly detection system that is in place. An anomaly is the unusual or unexpected behaviors in an information system .Anomalies violate the security policies of a system and they need early detection and counteraction else, they translate into real life negative situations. An anomaly detection scheme is a technical mechanism used to protect a computer infrastructure from attacks. Recently, there are several attack detection schemes. In order to benefit fully from, the anomaly detection concept, there should be additional security features like the authentication and access control protocols. An attack Detection System is a very important part of the entire system when developed with security in mind. The Anomaly Detection Schemes is not a new concept but it is in various applications with a promise of viable results. Lazarevic et al. (2003) compared various Anomaly Detection Schemes in a network to perform execution of data that was suspicious. Most of the organizations have adopted a system that suits them in detection and prevention of attacks .An example of such a system is the Intrusion Prevention System, which is very useful in preventing the Distributed Denial of Service attacks. Detection and prevention of th e collaborative attacks depends on several factors. Another such system is the STAND system, which is an improved version of CAD sensors discussed later in the prose. Change in time domain: All detection schemes require enough time for discovery of the attack and reaction to it. The attacks can be automatic, manual or semi-automatic. Automatic attacks leave no communication duration to the machine that is about to take place. The time parameters that determine the effect of an attack are reaction time; detection time and the response time. Many of the attackers make use of slow time dynamics of transmission time out. Here the attacker sends short-term bursts. In order to overcome the attackers in good time, there should be a means for real-time attack classification and a defense mechanism. This means that data mining by the detection system should be real-time, putting into consideration efficiency, accuracy, and usability, (Axelsson, 1999). To ensure high accuracy in a short time, data mining process uses programs that analyze the data and at the same time distinguish between genuine actions and malicious attacks. To ensure high efficiency, the costs of the extracted features are calculated and the cost approach is useful in production of efficient detection model. Usability improvement is by adapting algorithms that that facilitate fast updating of the system to enhance quick attack detection (Barbara et al., 2001; Barbara et al., 2002). Audit data analysis and mining (ADAM) is the system that proposes use of data

Autopsy of a Crime Scene Essay Example for Free

Autopsy of a Crime Scene Essay 1.Which technique is the best choice when blood is found at a crime scene? In the genetics laboratory (under resources at the bottom of the window), who is one individual that contributed to modern genetic analysis? What did this person contribute? I would say that analyzing the blood in a lab would be the best technique. Alec Jeffreys is known as the father of genetic profiling. He invented what is now an essential technique, especially in forensic science, called a polymerase chain reaction, or PCR. 2.How are computers used in fingerprint analysis? Experts examine tiny fingerprint details known as minutiae. These may be loops, dots, forks, islands, etc. Several comparison points must be perfectly matched for two fingerprints to be considered identical. 3.Who is a pioneer in fingerprint analysis? Describe a famous case that this person was involved in. Edward Foster studied fingerprint analysis in the US and introduced it to Canada. IN1911, Foster testified as a fingerprint expert in the Jennings case. Fingerprints in the wet paint next to Mr. Hiller, the murder victim, were the only clue. Foster demonstrated to the court that the prints of Thomas Jennings, who had been arrested as he was fleeing the scene, matched those left in the paint, and Jennings was convicted. 4.What is the role of the forensic chemist in crime scene investigation? These experts analyze all chemical, organic, and inorganic aspects of a sample. They separate the components and identify them using a variety of tests and devices. Their findings are used as evidence by the investigator and in court. 5.Who helped pioneer forensic chemistry? Describe one of her famous cases. France McGill became a pathologist and teacher is Saskatchewan. When Dr. McGill examined the stomachs of an elderly couple who had died on Christmas Day, she found a large quantity of strychnine, a powerful poison, along with the bran. The murder weapon was soon identified: the two of the victims had eaten bran muffins baked by their granddaughter. She had actually intended them for her father. She was charged with murder, but later acquitted. 6.In the ballistics laboratory, what is the water tank used for? Describe the analysis. To determine whether a bullet found at the crime scene actually came from the suspects weapon, it must be compared with  another bullet from the same gun. Ballistics experts fire it into a special water tank that slows and stops the bullet so that they can collect it intact. 7.Who helped pioneer ballistics analysis? What did he contribute? Wilfrid Derome was a multitalented Quebec doctor: a medico-legal expert, toxicologist, forensic photographer, medical examiner and scientific communicator. He founded the Laboratoire de recherchà © medico-legales de Montreal, the first laboratory in North America and only the third in the world. His motto: â€Å"Never allege anything you can’t prove.† 8.Why is measuring and diagramming the scene important? A police officer makes a sketch of the scene, measuring distances using measuring tapes and a laser meter. He notes the specific location of objects, Clues, and the body. The photos of this sketch will later be used to draw an accurate plan of the site on the computer. 9.What materials or tools would a crime scene technician use? A crime scene technician would use a camera to photograph the scene, a polilight to find clues that a rent visible to the naked eye, he would make diagrams and take measurements, they would use a magna brush and some type of colored powder to make any fingerprints more visible, and anything to properly take samples with. 10.From the activity and the information it had, what aspect of an investigation do you think you’d most like to work in? For example, would you prefer one of the laboratories? What appeals to you about this particular aspect of the investigation? I think I would like to work in a lab doing ballistics examination because I like to do a lot of puzzles and I believe that in some aspects it is like a big puzzle trying to figure out which gun fired the bullets at the scene.

Melting Pot of America :: essays research papers

Melting Pot of America Migrations As Population grew during the Paleolithic period, people wanted more space to live a roam about. Since they didn’t have a stable place to live, they were always moving and finding better places. Evidence indicates that the first peoples to migrate into America, coming from northeastern Siberia into Alaska (the Bering Straits), were carrying stone tools during Paleolithic period. They lived in groups of about 100. They used skin tents for shelter. They were nomadic, moving camp several times each year to take advantage of seasonal sources of food. Groups gathered a couple times a year to trade and gather valuable information that could be obtained about new sources of food or raw materials. It led families to move into new territory, eventually into Alaska and then farther south into the Americas. Evidence from the study of Native American languages, and materials, suggest that these earliest migrations may have taken place around 30,000 years ago. Bone tools, founded in Canada , have been discovered that have been radiocarbon-dated to 22,000 BC. Early Population It is estimated that at the time of first European contact, North and South America was inhabited by more than 90 million people: about 10 million in America north of present- day Mexico; 30 million in Mexico; 11 million in Central America; 445,000 in the Caribbean islands; 30 million in the South American Andean region; and 9 million in the remainder of South America. These population figures are a rough estimate (some authorities cite much lower figures); exact figures are impossible to ascertain. When colonists began keeping records, the Native American populations had been drastically reduced by war, famine, forced labor, and epidemics of diseases introduced through contact with Europeans. Europeans reactions Early Europeans were welcomed by the Native Americans to America. Native Americans viewed the visitors in amazement because of their clothing, ships, their technology (steel knives and swords, guns, mirrors, kettles) and other items unusual to the way of life of Native Americans. The ultimate goal for the Europeans was God, Gold, Glory, and it is because of this that ruined the good relationship between Europeans and the Natives. In the end the Europeans would overpower the Natives and would ultimately take their gold, have their glory, and make them believe in their god. Religion Most Native Americans believe that in the universe there exists an Almighty.

Hip-Hop Hold

John H. McWhorter's essay How Hip-Hop Hold Blacks Back discusses the popular subculture phenomenon of hip-hop and its effect on society. Recounting from experiences, McWhorther describes hip-hop as a counter-phenomenon which hinders the cultural and intellectual progress of the black community. Basing the development of hip-hop from the early 1960's to the 1970's, it emerged from the realism brought about by the oppression of the African-American community and how several ideologies, especially on activism, influenced the development of this genre.McWhorter argues on the effect of rap music as a means of creating a backward ideology; it does not provide any room for any intellectual development as far as culture is concerned. As such, he mentions in the end that rap music creates nothing. Rap revolution McWhorter states examples of historical implications of rap music. During the 1970's the idealism brought about by racial oppression, the black community raised different ideals towar ds apartheid and oppression, most notable of which were the ideals of African-American icons such as Malcolm X and Leroi Jones.The most famous of movements was the Black Panthers, a social group that inspired ideological activism as well as employing harsh measures in solidifying their claims. This gave rise to the ‘sticking it to the man' attitude, a kind of social behavior where authority does not apply and individuals tend to view themselves above such authority and law. From these ideologies, it also implies an individualistic notion towards the essence of rap music, which concentrates more on the life of a ‘gangsta' in the street, experiences on drugs, sex, and violence.According to McWhorter, rap music may be viewed as a cultural revolution of the society. That is, the message conveyed by these lyrics express a certain degree of the experiences of the past and conveying it as a detached attitude toward the status quo and authority. McWhorter used several words to d escribe rap music, and from such usage, his writing style clearly presents his bias against it, labeling the music as nonsense and profane. He also states rap music and ideology revolves mainly on the person's apathetic stance toward authority.As described by McWhorter, rap music retards black success since the music itself, according to him, only contains nonsense lyrics which celebrate street warfare, drugs, and promiscuity. McWhorter further mentions that ‘violence, misogyny, and lawlessness are nothing to sing about. He also explains the idea of ‘blaxploitation' which celebrates the idea of a black criminal as a revolutionary figure. This blaxploitation led to the development of the ‘gangsta' style, deviating from the early forms of rap as a ‘pop' or bubble gum music.Rap music is then associated with a constant mindset in disobedience and being above the system. From this point on, rap music has become another form of self-expression, concentrating more o n the aforementioned themes. The lyrics found in these rap songs have become edgy and tantamount to literal translation. As McWhorter mentions specific rap songs depicting these themes, he focuses more on the rapper's individual experiences, as described by the life in the ghetto marred with hardships and suffering.The songs then further downplays into more explicit themes such as detailed depictions of violence and problems against authority such as the inclusion of policemen and its association with violence. As such, these songs then represent explicit choice of word use in the lyrics which directly imply the use of guns and violence and their encounters with authority. McWhorter also adds that the ‘gangsta' type of rap are interspersed with mysoginistic views, viewing women as mere objects and prone to obsscene defamation as expressed in the lyrics.In this case, McWhorter states the use of these words adhere to sexual promiscuity and an apparent attack on the image of wome n. This presents another world-view, according to McWhorter, as he sums up the ‘gangsta' hip-hop genre with ‘Life ain't nothin' but bitches and money' (McWhorter, 4). He then points out that his kind of rap music can go old quickly and the rap music that can truly sell are those that are edgy, political, and representing another view with authority and society. Cultural influences From the aforementioned themes, rap music has then developed into an alternative culture, as it reinforces another kind of social behavior.The meaning implied by the lyrics used in rap songs produces another method of thinking, and from these implications, the behavior that the hip-hop world presents can be accepted as societal norms. The article presents a semi-critique of the notion on rap music and society. McWhorter associates the evolution of the music during the oppressive state of the black community during the sixties and seventies. He implies that rap music is a regressed state of musi c. He argues that although the can remain revolutionary in essence, the themes rap music tries to espouse is somehow degrading to the advancement of the black culture.He mentions the gesticulations, speech mannerisms as influenced by rap music can hinder young black men in searching for careers because of this unruly behavior they find in rap music. He also states that even as the media depict the successful African-American people in the industry, rap music, he argues, still depicts black people are uncivilized. The article is a semi-critique, that in a sense, it only presents the cultural implications of rap music and its adverse effect on society. However, it merely acts as a pure critique rather than a practical critique of rap ideologies.In a way, the article only acts as a reminder of this existing subculture and it does not give any practical situations in which the culture of rap can be addressed. However, the problem also lies on rap's history. Because of its uniqueness and the ‘stick it to the man' attitude, it has permeated through the societal mindset and has transformed into another phenomenological event of human concept. The ‘gangsta' mindset is now deeply ingrained through the consciousness of its audience and therefore can be hard for any critique to change. McWhorter's tone and word used clearly portrays his bias against the ‘nonsense' of hip-hop.This ‘nonsense' is viewed both in the linguistic and ideal sense. Rap music's choice of words is often explicit and profane, and it uses such words with constant repetition as though it is a part of the ‘gangsta' vocabulary. There is even an implication from the examples given by McWhorter that profane words in rap is in itself a standard and to be without such words, it cannot be considered hip-hop or rap. The lingual problem is also associated with gesticulations and speech mannerisms, according to McWhorter, that is considered ‘arrogant' and ‘irritating'.A ccording to the author, the theme that rap music revolves around is nonsense, since it only concentrates on the experience of the individual in his/her conditions supported by a formative mindset from the past. Sex, alcohol, violence and drugs are common themes in rap music, and these degrade the possibility of cultural advancement of a real society not hindered by any racial bias or oppression. Works Cited McWhorter, John H. â€Å"How Hip-Hop Holds Black Back. † The City Journal (Summer 2003).

A Collection of 20 Cute Love Quotes