Computer Hackers :: Essays Papers

Computer Hackers The meaning of Hacker is one who accesses a computer which is supposably not able to be accessed to non authorised people of the community. Hackers may use any type of system to access this information depending on what they intend on doing in the system. Methods Hackers may use a variety of ways to hack into a system. First if the hacker is experienced and smart the hacker will use telnet to access a shell on another machine so that the risk of getting caught is lower than doing it using their own system. Ways in which the hacker will break into the system are: 1) Guess/cracking passwords. This is where the hacker takes guesses at the password or has a crack program to crack the password protecting the system. 2) Finding back doors is another way in which the hacker may get access to the system. This is where the hacker tries to find flaws in the system they are trying to enter. 3) One other way in which a hacker may try to get into a system is by using a program called a WORM. This program is specially programmed to suit the need of the user. This programme continually tries to connect to a machine at over 100 times a second until eventually the system lets in and the worm executes its program. The program could be anything from getting password files to deleting files depending on what it has been programmed to do. Protection The only way that you or a company can stop a Hacker is by not having your computer connected to the net. This is the only sure fire way in which you can stop a hacker entering your system. This is mainly because hackers use a phone line to access the system. If it is possible for one person to access the system then it is possible for a hacker to gain access to the system. One of the main problems is that major companies need to be networked and accessible over the net so that employees can do overdue work or so that people can look up things on that company. Also major companies network their offices so that they can access data from different positions. One way which is used to try to prevent hackers gaining access is a program used by companies called a Firewall. Computer Hackers :: Essays Papers Computer Hackers The meaning of Hacker is one who accesses a computer which is supposably not able to be accessed to non authorised people of the community. Hackers may use any type of system to access this information depending on what they intend on doing in the system. Methods Hackers may use a variety of ways to hack into a system. First if the hacker is experienced and smart the hacker will use telnet to access a shell on another machine so that the risk of getting caught is lower than doing it using their own system. Ways in which the hacker will break into the system are: 1) Guess/cracking passwords. This is where the hacker takes guesses at the password or has a crack program to crack the password protecting the system. 2) Finding back doors is another way in which the hacker may get access to the system. This is where the hacker tries to find flaws in the system they are trying to enter. 3) One other way in which a hacker may try to get into a system is by using a program called a WORM. This program is specially programmed to suit the need of the user. This programme continually tries to connect to a machine at over 100 times a second until eventually the system lets in and the worm executes its program. The program could be anything from getting password files to deleting files depending on what it has been programmed to do. Protection The only way that you or a company can stop a Hacker is by not having your computer connected to the net. This is the only sure fire way in which you can stop a hacker entering your system. This is mainly because hackers use a phone line to access the system. If it is possible for one person to access the system then it is possible for a hacker to gain access to the system. One of the main problems is that major companies need to be networked and accessible over the net so that employees can do overdue work or so that people can look up things on that company. Also major companies network their offices so that they can access data from different positions. One way which is used to try to prevent hackers gaining access is a program used by companies called a Firewall.

Chemistry Energy Levels Essay

The energy of the subshell increases as follows:4s<4p<4d<4f * â€Å"4s† has the greatest probability of being close to the nucleus * Subshells are limited to # of electrons they can hold ( 2 electrons per orbital) s=21s orbital d=105d orbital p=63p orbitals f=147f orbitals Assessment * How many p subshells are in the 4th energy level (n=4)? 34px 4py 4pz * What is the maximum number of electrons that can occupy the 4p subshell? each p subshell can hold 2 electrons and therefore there are 3p orbitals with 2 electrons * What is the maximum number of electrons that can occupy the 4th energy 322n2=2(4)2 =2(16) =32 Creating Energy Level Diagrams * Used to show the relative energies of electrons in various orbitals under normal conditions * Each orbital is indicated by a separate circle/square * All orbitals of a given subshell have the same energy. Ie. The 3p orbitals in the 3p sublevels have the same energy * The spacing between successive subshells decreases as the number of subshells increases overlapping of shells having different values of n. Assessment 1. How many d orbitals exist? – 5 2. How many electrons can exist in the 3d orbitals? – 10-2 in each of the 5d orbitals 3. How many electrons can exist in the n=2 level? 8-remember 2n2=2(2)2=8 4. How many electrons can one 4f orbital hold? 14-2 in each of the 7f orbitals 5. Which has a higher energy a px, py, or pz orbital? They all have the same energy. 6. Which electron can be found furthest from the nucleus:2s or 3s? 3s electrons 7. Which electrons can be found furthest from the nucleus:2s or 2p. 2p is further. Fig. 3. 19 Arrow Orbital Notation Aka Orbital Diagrams * Use circles or squares for the orbitals and arrows for the electrons * RULES: * The Aufbau Principal- electrons will occupy lowest available energy level * Pauli Exclusion Principal- no two electrons have the same quantum numbers * Hund’s Rule – electrons remain unpaired for as long as possible. Ex: One electrons goes in each Px, Py, Pz, before they start to pair up Fig 3. 21 Electron Configuration – Provides the same information as an energy level diagram but in a more concise format. * Li: 1s2 2s1 C:1s2 2s2 2p2 * Ne: 1s2 2s2 2p? Use the following concept map to help to determine the filling order of the orbitals: * The similarity among elements within groups and the structure of the periodic table can be explained by electron configuration * Li: 1s2 2s1 * Na: 1s2 2s2 2p? 3s1 Short Hand Notation -Use symbol of noble gas with the same core electron configuration: Ex. Na [1s2 2s2 2p? ]3s1 Or [Ne] 3s1 Some unexpected Electron Configuration * Example: Cru and Cu Expected Actual Cr: [Ar] 4s2 3d? [Ar] 4s1 3d? Cu: [Ar] 4s2 3d? [Ar] 4s1 3d10 In each case, an electron is borrowed from the 4s subshell and placed in the 3d subshell. * Cr-3d subshell becomes half-filled * Cu-3d subshell becomes full * Half-filled and fully filled subshells tend to be more stable * Other expectations: Ag: [Kr] 4s2 3d10 Au: [Xe] 4f14 5d10 6s1 Explaining Ion Charges * Remember s electrons are lost before d electrons when dealing with transition metals. Ex1. Zn Zn: [Ar] 4s2 3d10 Zn2+: [Ar] 3d10 (4s electrons are lost so that the 3d orbital remains full) Ex2. Pb Pb: [Xe] 6s2 4f14 5d10 6p2 Pb2+: [Xe] 4f14 5d10 6p2 (The 6s electrons are lost) Pb4+: [Xe] 4f14 5d10 (The 6p electrons are lost as well as the 6s electrons) Quantum Numbers * Electron waves (orbitals) can be characterized by a set quantum numbers, n, l, ml, ms Principle quantum number (n): * Identifies the energy of an electron in an orbital * All orbitals that have the same value of n are said to be in the same shell * Range from n=1 to n=infinity * Determines the size of the electron wave how far the wave extends from the nucleus * As n increases the energies of the orbitals also increase Secondary quantum number (l): Divides the shells into smaller groups called subshells * n determines the values of l * for any given n, l may range from l=0 to l=n-1 * identifies the shape of the orbital Value of l| 0| 1| 2| 3| Letter designation| s(shape)| p(principle)| d(diffuse)| f(fundamental)| Magnetic quantum number (ml): * splits the subshells into individual orbits * identifies the orientation of the orbital * for any given value of l, ml has a value ranging from +l to –l * e. g. If l=0, ml=0; for l=1, ml=+1, 0, -1 which correspond to the x, y and z orientations of the p orbitals.

Managerial Finance Project Toys R - 1497 Words

Managerial Finance - 1 - Managerial Finance Project Toys R in Brazil Managerial Finance - 2 - Summary My paper term paper is 8 - page for my managerial finance class that analyzes the prospects of Toys R for international expansion into Brazil . The analysis consists of financial analysis of the company and en vironment analysis of the country. It relies on eight external sources presented in APA format. Body of the paper Introduction Toys R Us Inc., is a leading toy and baby products retail company that operates in a number of countries all over the world. St arted as a baby furniture store in 1948, the company has grown over the years into an international giant that runs 870 stores selling toys and baby goods in the†¦show more content†¦In 2011 the company formed a joint venture with Li Fung to cater to Southeast Asia and Greater China. Toys R went public in 1978 and operated as a public company until 2005 under this Managerial Finance - 3 - name, when it was taken over by an investment group, which allotted 1 share in the new entity for each share in the earl ier company (Toysrusinc.com, 2015) . Toys R market share peaked in 2011, when its sales touched $8,317 M giving it a market share of 19%. The market share of Toys R in the US has dipped in 2013 to its 2009 level of around 17.8% (Nasdaq, n.d.) Evaluation of the Company’s Financial Stability The company has a good short - term liquidity position, but it is over leveraged. The equity has become negative and the company has been making losses in the last two years. Obviously, the company is not in a position to g enerate additional cash required for investing in foreign operations either through internal generation or by raising external funds. Consequently, it is suggested that the company should look at foreign expansion w ith minimum capital investment by transfe rring essential assets that can be spared from the parent company. The balance of the capital requirement should be met through local long term loans. Key Financial Figures Relevant financial figures of the company were obtained from the published financi al statements and are shown in Appendix