The Welding Manufacturing Process Engineering Essay

The Welding Manufacturing Process Engineering Essay Welding is an attractive topic to be researched because it is used in the majority of industrial fields and manufacturing processes. The next figure shows that the shield metal arc welding process represents about 42% from the whole welding processes. The welding theory depends on the joining between two parts whether metals like aluminium, steel, copper, or cast iron or plastics like polypropylene. Welding specially is different from the normal joining where the aim of welding is to obtain a strong joint between two or more parts to be as a single part and to minimize number of parts. For example, the mechanical joints used to assemble pipe lines is limited to specific values of pressure and temperature and when those values exceed those limits, the welding takes place in the assembly process The main concept of fusion welding is the partial melting and fusion of the joint between two members and a filler metals may be used. In the arc welding process, the heat required is obtained from electrical energy. An arc is produced between the tip of the electrode and work piece to be welded, by using an AC or a DC power supply. Shield metal arc welding (SMAW) is one of the oldest, simplest, and most versatile joining processes. About 50% of all industrial and maintenance welding at present is performed by this process. The electric arc is generated by touching the tip of a coated electrode with the work piece or the sample and moving back it quickly to enough distance to maintain the arc. The heat generated melts a piece of the electrode tip, its coating and the base metal in the immediate arc area and this mixture forms the weld when it solidifies. 1.2 Aims objectives The aim or goal of the research is a broad statement of the problem which I intend to solve and what I intend to achieve. Objectives  set the realistic targets to achieve during the research and I should use best practice in project management. Objectives are derived from the aim, but are more specific and measurable. Aims: Investigate/research solutions to reduce cracks occurring in carbon steels during shield metal arc welding process Objectives: Investigate/research shield metal arc welding process in carbon steel metals Investigate/research parameters affecting shield metal arc welding process in carbon steel metals Investigate/research reasons of cracks in shield metal arc welding process in carbon steel metals and methods to reduce them. Literature review Many researches were done to investigate welding processes from many points of views and in the next pages these examples will be shown below: First example:- In the research done by G. B. JANG, H. K. KIM AND S. S. KANG, It was discovered that in the steel bridge manufacturing, there are many differences in dimensions caused by weld deformation often happen because multi-pass welding is used mainly to join thick plates. It repeatedly produced that root openings are out of tolerances at place of butt joints. Second example:- In the research done by G. B. JANG, H. K. KIM AND S. S. KANG, It was discovered that there is a new innovative method for estimating the actual cooling rate in a welded section is existed. This method is depended on applying a weighting factor to the Rosenthal* analytical solutions for thick and thin plates. The factor is calculated from the heat affected zone (HAZ) width obtained from carved sections and reflects the actual response of the plate to the heat flow condition. The formulations used in the literature of this research are depended on the assumption of thin plate and thick plate conditions while most actual conditions not real somewhere between the two extremes. Limited experimental measurements of cooling rate performed by instrumented welding presented good agreement with predicted values. The model was further used to get the peak temperature profile across the HAZ. 2.1 Methodology: As shown in the literature review, the previous two researches concentrated on the problems related to weld deformation and cooling rate.In this research the study of shield metal arc welding will be concentrated on the parameters affecting cracks appearance and the methods used and available to reduce and eliminate them. To achieve objectives, first, a study will be done to previous researches in the same field through the internet and reading different types of books to study the Methodology Block Diagram: SMAW process in carbon steels.the next step is to focus on cracks appeared and how to reduce them. Also Libraries, internet, will be used as a statement of method. The internet usage will give powerful to the research to get data now because it is fastest, cheapest, and most widely in getting data and information that needed in any section of science. Different search engine will be used as www.google.com www.yahoo.com In addition, the forums will be used to discuss results with other engineers to have learning from their experts. Libraries: from reading books you can know the theoretical part and the analysis of the welding parameters. In this study, there is no practical work but if there was a similar one in the future it must take into considerations the ensure that the final product must be safe to the environment by taking into consideration to prevent any harmful fumes. Conclusion:- After this brief proposal it can be said that this project will concentrate on three main categories:- Shield metal arc welding process in carbon steel metals Parameters affecting shield metal arc welding process in carbon steel metals Reasons of cracks in shield metal arc welding process in carbon steel metals and methods to reduce them. Also, it can be guessed that the weakness of this proposal is not mentioning many problems related to this process and a try will be done overcoming this point in the next stages of the project. This proposal takes its strength from the variety and spread of SMAW process in the industrial field as shown in the beginning of the proposal. Time Table: Completed proposal 9TH of October Initial project proposal word 3rd 11th of November Start collecting information and data 1st December-6th Start following chapter 25th December Prepare slideshow 1st January-5th Complete interim report 18th of January Work on following chapters 10th of February Project should almost be complete 10th of march Prepare for presentation 7th of may Chapter 3 Arc welding concept Arc welding is a process of the fusion welding processes which contains:- 1 Arc welding processes (non consumable electrodes) Gas tungsten arc welding Plasma arc welding Atomic hydrogen welding 2 Arc welding processes (consumable electrodes) Shielded metal arc welding Submerged arc welding Gas metal arc welding Flux cored arc welding Electro gas welding Electro slag welding 3 Electron beam welding 4 Laser beam welding The main concept of fusion welding is the partial melting and fusion of the joint between two members and a filler metals may be used. In the arc welding process, the heat required is obtained from electrical energy. An arc is produced between the tip of the electrode and work piece to be welded, by using an AC or a DC power supply. Shield metal arc welding (SMAW) is one of the oldest, simplest, and most versatile joining processes. About 50% of all industrial and maintenance welding currently is performed by this process. The electric arc is generated by touching the head or the tip of a coated electrode against the work piece and withdrawing it quickly to a distance sufficient to preserve the arc. The heat start generating from the electrode tip, its coating and the base metal in the immediate arc area and this mixture forms the weld when it solidifies. 3.2 Classification of arc welding The arc welding classified into many types used in the industrial field each one have advantages and defects different from the other type, So that the user select the required type according to the requirements and the economy aspects. In the below figure we show for the classification of arc welding which appear in the industrial (3.1) Arc welding PAW ESW MIG TIG SAW SMAW Carbon arc welding Figure 3.1 arc welding classification Chart key SMAW: shield metal arc welding SAW: submerged arc welding TIG: tungsten inert gas arc welding MIG: metal inert gas welding PAW: plasma arc welding ESW: electro slag welding The above chart list for the types of the arc welding which used in the industrial fields. Advantages of arc welding There are some characteristic for the arc welding rather than the another methods to joining metals which it represent the advantages of the arc welding listed as below 1- Strong and tight joining 2- Cost effectiveness ( arc welding have low capital and running costs) 3- Simplicity of welded structure design Figure 3.2: arc welding usage in the industry (http://64.78.42.182/sweethaven/BldgConst/Welding/lessonmain.asp?lesNum=4modNum=1) 3.2.1 Principals and definition Shield metal arc welding (SMAW) consider as process in which coalescence of metal produced by the heat which generated from the electric arc that it maintained between the tip of the consumable electrode and the base metal in the welding region. The next figures show the circuit used in the shield metal arc welding Figure 3.2: SMAW system, http://www.millerwelds.com/pdf/guidelines_smaw.pdf Figure description: the above figure illustrate the main parameters used in the SMAW process Power supply The shield arc welding power source provides constant current (cc) it may be alternative current (Ac) or direct current (DC) depending on the electrode being used, but the best welding usually used the direct current (DC) as power supply for the circuit. The amount of power required to welding process calculated from the relation (P= IV) Where I represent the current V represent the voltages In the selection process for the power supply we notice that the voltage equal to constant value so that the current is the main parameters in the selection process which discussed in the next section 3.2.2 Current setting The amount of current needed to melt the work piece and the electrode tip depends on several factors as 1- Type and position of the joint 2- Work piece type and its thickness 3- Electrode type and its diameter In facts most of welder select the current depending on the diameter of the used electrode which it measured from the inner section without the coated diameter as showing in the below figure: No Code Usage and properties 1 6010 all welding positions result in deep penetration weld work on rusted, dirty, or painted metals 2 6011 used with ac and dc currents all welding positions result in deep penetration weld work on rusted, dirty, or painted metals 3 6013 used with ac and dc currents result in medium penetration weld give superior weld bead appearance 4 7018 low hydrogen electrode can be used with dc or ac can result in welds of x-ray quality with medium penetration must be kept dry 1 80LV Red used in AC/DC straight or reverse polarity all positions with low voltage machines 2 275 high yield and tensile strength 3 24 AC/DC ac/dc all position electrodes join dissimilar metals 4 309 L AC/DC high corrosion resistance high strength all position electrodes Table 3.3: Examples of electrodes usage and properties A basic guide of arc welding electrodes by Bruce Bauerlein http://www.metalwebnews.com/howto/weldrod.html http://www.weldershop.info/282/types-of-welding-electrodes/ 1. Electrode The electrode used in (SMAW) process consist from metal rod coated in metal mixture called flux which gives off gases as it decomposes to prevent weld contamination , introduces deoxidizer to purify the weld , causes weld- protection slag and to provides alloyelements to improve the quality of weld. There are three types from the electrode used in (SMAW) process which discussed below. Fast fill electrode: this type from electrode is designed to melt very fast so that means the welding speed should be maximized. This type used when we weld in the normal case in vertical welding so we can weld with high speed so we use this electrode type. Fast freeze electrode: this type from electrode designed to solidify quickly making welding in different positions by preventing the weld pool from shifting. Intermediates electrodes : the commonly used type and it intermediate in two case melting and in freezing but if we weld with high speed with using this type we get poor quality so that this type is not suitable in case of high speed. The American welding society established system that used to assign electrodes by using four or five digital number. Covered electrodes made of mild steel or low alloy steel carry the symbol of (E) followed by special numbers. The first two or three digits of the number of the electrode specify the tensile strength of the weld metal. The mid digits generally identify the welding positions allowed with the electrode normally using the values 1 (normally fast-freeze electrodes, implying all position welding) and 2 (normally fast-fill electrodes, implying horizontal welding only). The welding current and the type of the electrode casing are specified by the last two digits together. Example for electrode serial number E7018 E indicates electrode 70 indicates 70,000 psi tensile strength 1 indicates use for welding in all positions 8 indicates low hydrogen 2. Cables: there are two cables work cable which connected the base metal and the electrode cable which connected to the electrode one of them represent positive and the other represent the negative side this according to the polarity of the welding process 3.2.3. Welding trouble shooting This section discuss to the trouble shooting may faced it during the welding speed as 1-Porosity: small cavities or holes resulting from gas pockets in weld metal. Fig 3.4: porosity of welding www.miller.com.pdf The porosity in welding it may be caused by the dirty on work piece and the corrective action to face it by Remove all grease, oil, moisture, rust, paint, coatings, slag, and dirt from work surface before welding. 2-Excessive Spatter: scattering of molten metal particles that cool to solid form near weld bead as shown in the below figure. Fig 3.5: excessive spatter www.miller.com.pdf The main causes to excessive spatter is the current too high for electrode and it avoid by decrease current or select larger electrode. 3- Distortion: contraction of weld metal during welding that forces base metal to move. Fig 3.6: Distortion www.miller.com.pdf Distortion in the welding appear as result to excessive heat input. And there is many ways to solve this problem as 1-Use restraint (clamp) to hold base metal in position 2-Make tack welds along joint before starting welding operation. 3-Select lower amperage for electrode. 4-Increase travel speed 5-Lack of Penetration: shallow fusion between weld metal and base metal. Fig 3.7: lack of penetration www.miller.com.pdf The lack of penetration appears as result for many causes as showing below: Possible causes Corrective action Improper joint preparation Material too thick. Joint preparation and design must provide access to bottom of groove. Improper weld technique. 1-Keep arc on leading edge of weld puddle. 2-Reduce travel speed. Insufficient heat input. Increase amperage. Select larger electrode and increase amperage Table 3.8: causes of penetration lack Advantages of shield metal arc welding The shield arc welding have main further that represent the advantages as below 1-Strong and tight joining rather than the other methods 2-Cost effectiveness (have low capital and running cost) 3- The arc welding Simplicity of welded structures design 4- May be mechanized and automated or manual in some duty Disadvantages of arc welding The using of the shield metal arc welding lead to some defects as 1- Internal stresses, distortion and change for the microstructure in the weld region 2- Have harmful effects as radiation and fumes 3.3 Application of the shield arc welding The arc welding it can be used in many applications as: 1-Buildings and bridges structures 2-Automotive, ship and aircraft constructions 3-Pipe lines 4-Tanks and vessels (2.2) 3.4 Polarity: To introduce what the polarity means and the different type of the polarity, first of all the project will show what is the difference between AC and DC? 3.4.1 AC and DC current What is the AC current? It means alternating current. In this current the electric charge flow periodically reverses direction. The electric charge in this case will move for instance backward then it will reverse the direction again to move forward, then backward then forward over and over again. The waveform for alternating current is a sine wave. But sometimes in certain applications the waveform differs like square wave or triangular wave. acFile:Types of current by Zureks.svg triangleRMS_fig_1 Figure 3.9 current and wave types Dc current What is the DC current? It means direct current because the electric charge in direct current moves in a constant direction, and that is the difference between DC and AC. The DC could be produced by such sources like thermocouples, batteries and solar cells. We can use a rectifier which is a current-switching arrangement to obtain direct current from an alternating current. The concept of rectifier is containing electromechanical elements or electronic elements which allow current to flow only in one direction. File:Current rectification diagram.svg Figure 3.10 current rectification diagrams 3.4.2 AC and DC welding machines: The welder or welding machine is the power source that we used in arc welding. There are three basic types of welding  machines used now which are rectifiers, motor- generators and transformers Motor generator welding machines (direct current welding machines): The motor generator could be powered by diesel, electrical or gasoline motor. We can use the gasoline and diesel motors in places where the electricity is not available or hard to reach it like deserts. With these machines we could generate either direct or alternating current. There are new and old machine types of these machines, the older type require reversing the cable connections in order to change the polarity. But in the new machines you can change the polarity from welding in the direct current mode to alternating current mode by turning a switch. The advantages of a (dc) welding generator: The main advantage of a direct-current (dc) welding generator is that you can weld with either reverse or straight polarity. Almost we can weld all ferrous and non-ferrous metals. We can use DC in practically all welding operations so we can consider that DC is most universal in application. The output of generators like rectifier and transformer a sets is not affected by normal variations in power line voltage. Diesel driven generators form self-contained units. Disadvantages of a (dc) welding generator: The initial cost is high The machine operation is noisy The maintenance cost is high AC transformers welding machines: The static-transformer type is the arc welding machines that we used in alternating current. http://www.tpub.com/content/construction/14250/img/14250_134_2.jpg The advantages of these types of  machines are lightest, smallest and least expensive welders made. We can use 200, 300, and 400 ampere ratings for manual operation in industrial  applications. But in light industrial, job/shop and garage welding we could use machines with a 150-ampere rating. These types of transforms equipped with arc- stabilizing capacitors. The advantage of a (AC) transformer welding machine: The main advantage of (AC) transformer welding machine is the freedom from arc blow. The arc blow causes the arc to wander while you are using large coated electrodes or welding in corners on heavy metal. The arc blow often occurs when welding with direct current machines. Polarity What is the polarity? Figure 3.12 Straight and reverse polarity in electric welding .Polarity is the direction of the current flow in a circuit. There are two types of polarity reverse polarity and straight polarity. In the straight polarity the work piece is positive and the electrode is negative. The electrons move from the electrode to the work piece. In the reverse polarity the work- piece negative and the electrode is positive. The electrons move from the work piece to the electrode ac and dc current was briefly covered. http://www.tpub.com/content/construction/14250/img/14250_141_2.jpg The effect of polarity: The polarity affects the amount of heat which is going to the base metal. You can direct the amount of heat to where it is needed as per the application you working in by changing the polarity. If you want to direct the majority of heat toward the work piece, you must use straight polarity. That type of polarity being used in some welding situations when it is desirable to have more heat on the work piece because of its size to melt the base metal than the electrode. We can use straight polarity for all mild-steel, bare, or lightly coated electrodes. If you want to concentrate the heat on the electrode, you can use reverse polarity because in this type less heat is concentrated at the work piece which allow filler metal to cool faster, giving it greater holding power because of this reverse polarity is being used when you are making vertical and overhead welds. Reverse polarity could be used in the welding of nonferrous metals such as bronze, aluminum and nickel. 3.5 Heat Affected Zone 3.5.1 Heat affected zone definition. The heat affected zone (HAZ) represented by the area of base material subjected to the high heat in order to achieve the welding process. The area which subjected to change in its microstructure and mechanical properties. SMAW process give a highly heat concentration in specified region called (fusion zone), produced in the region of heat affected zone. To calculated the amount of heat in the HAZ the following formula used. Q =60 VI / 1000S Where Q = heat input (kj/mm), V = voltage (V), I = current (A), and S= welding speed (mm/ min). (2.10) The molten occur in the fusion region not in the heat affected zone. So that the HAZ heated to a high enough temperature for sufficient period that grain growth occurred. Heat affected zone is that location of the base metal which in it the mechanical properties and the microstructure have been affected by the heat of welding process. The heat affected zone is subjected to a complex thermal cycle (sudden heating followed by rapid cooling) in which all temperatures from the melting range of the metal down to much lower temperatures are involved and HAZ therefore consists of a series of graded structures ringing the weld bead. HAZ usually contains a variety of microstructures different from the remaining part from the base metal. The width of HAZ varies according to the welding process and technique; in arc welds it extends only a few mm from the fusion boundary, The HAZ in most metal welding process of normal structure welded in one run with coated electrodes that to classify it to four basic region. 3.6 Classification and Designation The classification of electrodes is done by one of the three following categories:images 1 Strength of the deposited weld metal 2 Current (ac or dc) Figure: 3.13 Shield metal arc welding electrodes3 Types of coating The identification of electrodes is by numbers and letters as shown in the next table. Typical coated electrode dimensions are in the range of 150 to 460 mm (6 to 18 in.) in length, and 1.5 to 8 mm (1/16 to 5/16) in diameter. Specifications for electrodes and filler metals (including dimensional tolerances, quality control procedures, and processes) are published by the American welding society (AWS) and the American national standards institute (ANSI). Some specifications appear in the aerospace materials specifications (AMS) by the society of automotive engineers (SAE). Electrodes are sold by weight and are available in a wide variety of sizes and specifications. 3.7 Electrodes types and choices When the choice of a suitable electrode is needed, many considerations are taken such as 1 Quality of weld 2 Penetration 3 Used current whether AC or DC 4 Crack resistant CHAPTER 4 Defects appears in carbon steel welding Carbon steel Carbon steel which it called also the plain carbon steel or the Mild Steel .It does also mean the steel where the main alloying element is carbon. When the carbon steel is specified minimum for copper does not exceed 0.40 percent and when the maximum content is specified for one of the following elements does not surpass the percentages known (manganese 1.65, silicon 0.60 and copper 0.60). The term carbon steel could also be used in position of steel which is actually not stainless steel, so the uses of carbon steel may contain alloy steels. The low carbon steel has some properties similar to the properties of iron. As the content of the carbon going up, the metal becomes with some advantages such as harder and stronger and the disadvantages are less ductile and very hard or difficult to weld. Higher carbon steel usually has the lower the melting point and lower temperature resistance. Carbon steel content effects in yield strength of steel because carbon atoms are fit into the interstitial crystal lattice the places of the body-centered cubic (BCC) collections of the iron atoms. The spaces in carbon steel reduce the mobility of dislocations. To get dislocations to move, a high sufficient stress level should be applied to imbalances for the dislocations to separate them. All this happen because the spaces or the places of the carbon atoms cause in some of the iron BCC lattice cells to deform. Carbon steel is steels whose alloying elements do not exceed the following limits: Element Max weight % C 1.00 Cu 0.60 Mn 1.65 P 0.40 Si 0.60 S 0.05 4.2 Carbon steel properties and classifications: Carbon steels could be specified by chemical compositions, mechanical properties and thermal treatments. The following table shows the typical properties of steels with room temperature in (25 °C). The wide ranges of final the tensile strength, yield strength, and hardness are mostly due to the different between the heat treatment conditions. The different between the heat treatment conditions comes from the wide range of the the tensile strength, yield strength and hardness. Properties Carbon Steels Alloy Steels Stainless Steels Tool Steels Density (1000 kg/m3) 7.85 7.85 7.75-8.1 7.72-8.0 Elastic Modulus (GPa) 190-210 190-210 190-210 190-210 Poissons Ratio 0.27-0.3 0.27-0.3 0.27-0.3 0.27-0.3 Thermal Expansion (10-6/K) 11-16.6 9.0-15 9.0-20.7 9.4-15.1 Melting Point ( °C) 1371-1454 Thermal Conductivity (W/m-K) 24.3-65.2 26-48.6 11.2-36.7 19.9-48.3 Specific Heat (J/kg-K) 450-2081 452-1499 420-500 Electrical Resistivity (10-9 m) 130-1250 210-1251 75.7-1020 Tensile Strength (MPa) 276-1882 758-1882 515-827 640-2000 Yield Strength (MPa) 186-758 366-1793 207-552 380-440 Percent Elongation (%) 10-32 4-31 12-40 5-25 Hardness (Brinell 3000kg) 86-388 149-627 137-595 210-620 www.efunda.com The following groups show the subdivided of the plain carbon steel: Low Medium High Very high Low The low carbon steel has another name which is frequently called mild steels. Low carbon steel has less than 0.30 percent carbon and its one of the most commonly used. They machine and weld nicely and are more ductile than higher-carbon steels. Medium The percentage of medium carbon steel is between 0.30 to 0.45 percent. When the carbon increases thats mean increasing in hardness and tensile strength and decreasing in ductility and more difficult machining. High The high carbon steel contains carbon which starts from 0.45 to 0.75 percent of carbon. These steels can be challenging to weld. Preheating or the post heating (which is useful to control the cooling rate). Heating during the welding process become very important or necessary to produce acceptable welds and to control the mechanical properties of the steel after welding. Very High With more than 1.50 percent of carbon content in very high carbon steel

Manipulation and Prejudice in Othello Essay

The tragic play ‘Othello’, written by William Shakespeare, is one where the direct impact of themes such as jealousy, prejudice, and manipulation bring about the downfall of the protagonist Othello, a moor who is both a successful military leader in the city of Venice and the lover of the ‘Sweet Desdemona’. The Antagonist, Iago, weaves webs of deceit and denigrations on almost all of the characters and is portrayed as the puppet master, controlling the characters to his own end. The imagery associated with the central theme of jealousy suggests destructive, terrifying and perhaps unnatural qualities of this emotion. It is ‘the green-eyed monster, which doth mock / the meat it feeds on’. There is a strong sense of devouring and being devoured in these images, which fits in with Iago’s description of Othello as being ‘eaten up with passion’. These lines suggest the exact quality of Othello’s monumental jealousy; once he becomes convinced that his wife is unfaithful, his jealousy does indeed feed on itself, leading the protagonist to become dehumanised and animalistic. Jealousy is also deeply humiliating in ‘Othello’; Iago is correct when he says that it is ‘a passion most unsuiting such a man’. There are three examples of jealousy that are explored by Shakespeare in ‘Othello’. Iago’s personal and professional jealousy, which is linked to feelings of envy and sets events in motion. This is demonstrated through the use of soliloquy where Iago expresses his hate and jealousy of Cassio when he was given a position that Iago thought he should have gained. The use of soliloquy adds dramatic tension as Iago expresses his motive for revenge to the audience before enacting out his plans on the unsuspecting characters. The second example is of Bianca’s suspicions, which help Iago with his manipulation of the Othello adding to the dramatic tension and the third example of jealousy is of the Moors towering jealousy. Othello’s character arc is somewhat depended on his feelings of jealousy when he assumes his wife Desdemona is ‘a strumpet’. The language that is used by Othello at the start of the play is in blank verse, unrhymed iambic pentameter. This structuring of the dialogue characterises Othello as educated, dignified and authoritative. However, this is juxtaposed at the end of the play where there is little to no structure in Othello’s dialogue, often composed of short outbursts, characterises the protagonist as animistic, unhinged and weak. The theme of prejudice is also prominent in the play ‘Othello’. The cultural difference between the Moor and the general white Venetians serves as an impetus for conflict between the characters. The first instance of racial prejudice almost opens the play in Act 1 Scene 1 with the dialogue between Iago and Brabantio, ‘even now, an old black ram is tupping your white ewe’. The animal imagery Iago employs when speaking of Desdemona’s copulation with Othello is firstly highlighting the racial difference between both Othello and Desdemona and secondly, relating interracial relationships as animalistic through dehumanising imagery. Many of the references to Othello in regards to his colour and creed are typically negative, though are undermined because the audience understands the motives of both Iago and Roderigo. He is also described as ‘sooty’ and ‘thick lips’, which help to construct a negative characterisation of Othello. So far as dislocation is concerned, an aspect of the tragedy comes about because Othello is characterised as an outsider, he is in an weak position of being a black man in a white society. This dislocation is furthered through the marrying of a white woman and through holding a high positioned rank in the military. This is one of the reasons that Othello is subject to manipulation by Iago on racial grounds, and on Rodrigo’s racist ideology.

American Stereotypes of China

US writer Todd C. Ames concludes his two-part discussion of the ways in which Chinese and Americans think of each other, and the most common misunderstandings that arise AMERICANS don't know much about China. What they do know comes from three main sources: movies, the news, and history classes. This can be a sensitive subject, and I do not wish to offend anyone – my goal is only to give you an overview of American stereotypes of China. Just as I have encountered many stereotypes that the Chinese have of America (some accurate, some absurd, some insulting), one can similarly encounter American stereotypes of China in the US. All Chinese know kungfu and dress like Huang Feihong. (Source: Jet Li, Jackie Chan, and Bruce Lee [Li Xiaolong] movies). – Anything to do with China is â€Å"ancient† and â€Å"mysterious. † (Source: the fact that Chinese language seems to be made up of â€Å"mysterious symbols† to Western eyes, movies about Chinese history). All Chinese are â€Å"brainwashed† into worshipping Chairman Mao and can't think independently. (Source: studying the Cultural Revolution in high school history classes. ) – â€Å"Guangdonghua† (Cantonese) is the official language of China. Source: Hong Kong movies, Chinese-American immigrants who came to the US from Guangdong and Hong Kong during the 19th and 20th centuries). – Chinese culture is basically the same today as it was 1,000 years ago (eg, â€Å"traditional, conservative, polite,† etc. ). (Source: studying Chinese history without being familiar with modern China). – In China, no one can express any idea that isn't approved by Chairman Mao – if you do express an â€Å"unapproved† idea, you will be instantly sent to jail or shot. (Source: studying the â€Å"cultural revolution† (1966-76)in high school history classes, the events of 1989 in Beijing). Chinese (and all â€Å"Asians†) are good at maths. (Sou rce: I don't know). – China and Japan are basically the same. (Source: ignorance). – â€Å"Asian† women are generally subservient to men, anti-feminist, and more â€Å"morally pure† than Western women. (Source: movies about ancient Japan, cultural differences. This stereotype is again the result of ignorance of modern China – and thinking that today's China is really 12th-century ancient Japan). Chinese stereotypes of US As an American, I can give you a unique perspective on the Chinese stereotypes of the US that I have encountered. Some of them really made me laugh – as I'm sure some of the above American stereotypes of China made you laugh. – Americans don't care about their families very much. The opposite is true. Almost every American will tell you that family is the most important thing in life. – Most Americans have AIDS and have sex in the streets. I'm still laughing at this one. One of my friends told me that she thought this was true before coming to the US. – Mixed ethnic background = intelligence. The more mixed your ethnic background, the smarter you must be. This kind of thinking is truly confusing and shocking to most Americans. Many Americans would even consider this kind of thinking â€Å"racist,† as some sort of inversion of Hitler's â€Å"race purity† theories. In any case, I was really surprised to hear this from virtually every Chinese I know. Almost all Americans have a diverse and mixed ethnic background – so we must all be geniuses. – All American men are â€Å"se lang (lecher). † (Source: cultural differences. ) – The crime rate is so high in the US that your life is always in danger. This is a vast exaggeration. The US has the most socially liberal society in the world, especially when it comes to sex. This idea comes from Hollywood – and it couldn't be more false. The US in general (especially the Midwest) is very socially conservative. Virtually every European country has a much more â€Å"liberal† and â€Å"open† view of sex and social relations in general comp ared to the US. In my opinion, the US is closer to China in this respect than to European countries. You probably don't believe me, but if you get to know some Americans, you will see that it is true. As far as social relations and sex go, I would put Japan and Europe in one category. And I would put China and the US in one category. – All â€Å"Western† countries are basically the same. This stereotype is the mirror of the American stereotype that all â€Å"Eastern† countries (China, Japan, Korea, etc. ) are basically the same. Both stereotypes are completely false and are purely based on the perception that â€Å"all foreigners look alike. † – Most American college students don't study, party all of the time, and are ignorant of the outside world. This stereotype is pretty accurate. – Every American owns a gun. Roughly 25 per cent of American adults own a gun, which is extremely high compared to most other countries. But still, the vast majority of Americans do not own guns. Food In general, Americans love Chinese food. Chinese and Italian food are probably the two most popular types of food in the US. However, most of the Chinese food you will find in US restaurants is â€Å"Americanized. † You probably won't find things like stomach or intestines on the menu. Also, pork is not so popular in the US. Beef and chicken are much more popular in the US than pork. So don't be surprised if many Americans you meet don't like pork. One â€Å"food stereotype† that I have encountered among Chinese (and everyone else outside the US) is that all Americans eat McDonald's. I don't have any friends who like McDonald's. I hate it. Everyone I know hates it. I think McDonald's is probably more popular in other countries than it is here in the US. Of course, it is popular to some degree; but it tends to be more popular among certain segments of society than others.

Claremont McKenna Acceptance Rate, SAT/ACT Scores

Claremont McKenna College is a private liberal arts college with an acceptance rate of 9.3%. Located 35 miles east of Los Angeles, Claremont McKennas 50-acre campus is located in the heart of The Claremont Colleges, a consortium of seven schools. Students at CMC share facilities and can cross-register for classes at schools in the consortium including  Scripps College,  Pomona College,  Harvey Mudd College, and  Pitzer College. Claremont McKenna has an 8-to-1  student/faculty ratio, a diverse student body, and strong liberal arts credentials that earned it a chapter of  Phi Beta Kappa.   Considering applying to this highly selective school? Here are the Claremont McKenna admissions statistics you should know. Acceptance Rate During the 2017-18 admissions cycle, Claremont McKenna had an acceptance rate of 9.3%. This means that for every 100 students who applied, 9 were admitted, making Claremont McKennas admissions process highly competitive. Admissions Statistics (2017-18) Number of Applicants 6,272 Percent Admitted 9.3% Percent Admitted Who Enrolled (Yield) 56% SAT Scores and Requirements Claremont McKenna requires that all applicants submit either SAT or ACT scores. During the 2017-18 admissions cycle, 51% of admitted students submitted SAT scores. SAT Range (Admitted Students) Section 25th Percentile 75th Percentile ERW 670 730 Math 680 770 ERW=Evidence-Based Reading and Writing The admissions data tells us that most of Claremont McKennas admitted students fall within the top 20% nationally on the SAT. For the evidence-based reading and writing section, 50% of students admitted to Claremont McKenna scored between 670 and 730, while 25% scored below 670 and 25% scored above 730. On the math section. 50% of admitted students scored between 680 and 770, while 25% scored below 680 and 25% scored above 770. Applicants with a composite SAT score of 1500 or higher will have particularly competitive chances at Claremont McKenna. Requirements Claremont McKenna does not require the SAT writing section or SAT Subject tests. Note that Claremont McKenna participates in the scorechoice program, which means that the admissions office will consider your highest score from each individual section across all SAT test dates. ACT Scores and Requirements Claremont McKenna requires that all applicants submit either SAT or ACT scores. During the 2017-18 admissions cycle, 56% of admitted students submitted ACT scores. ACT Range (Admitted Students) Section 25th Percentile 75th Percentile English 32 35 Math 28 33 Composite 31 34 The admissions data tells us that most of Claremont McKennas admitted students fall within the top 5% nationally on the ACT. The middle 50% of students admitted to Claremont McKenna received a composite ACT score between 31 and 34, while 25% scored above 34 and 25% scored below 31. Requirements Claremont McKenna does not require the ACT writing section. Unlike many schools, Claremont McKenna superscores ACT results; your highest subscores from multiple ACT sittings will be considered. GPA Claremont McKenna College does not provide data about admitted students high school GPAs. Self-Reported GPA/SAT/ACT Graph Claremont McKenna College Applicants Self-Reported GPA/SAT/ACT Graph. Data courtesy of Cappex. The admissions data in the graph is self-reported by applicants to Claremont McKenna College. GPAs are unweighted. Find out how you compare to accepted students, see the real-time graph, and calculate your chances of getting in  with a free Cappex account. Admissions Chances With an acceptance rate of just over 9%, Claremont McKenna College is  one of the countrys  most selective colleges. However, Claremont McKenna has a holistic admissions process involving other factors beyond your grades and test scores. A strong application essay and glowing letters of recommendation can strengthen your application, as can participation in meaningful extracurricular activities and a rigorous course schedule. Students with particularly compelling stories or achievements can still receive serious consideration even if their test scores are outside Claremont McKennas average range. In the scattergram above, the blue and green dots represent accepted students. You can see that the majority of successful applicants had A averages, SAT scores of about 1350 or higher (ERWM), and ACT composite scores of 29 or higher. The higher those numbers, the better your chances of receiving an acceptance letter. Note that there are many red dots (rejected students) and yellow dots (waitlisted students) hidden behind the green and blue of the graph. If youre applying to Claremont McKenna College, you should  consider the school a reach  even if you have exceptional grades and standardized test scores. The graph above illustrates why. Many students with unweighted A averages and extremely high standardized test scores were still rejected by Claremont McKenna. All admissions data has been sourced from the National Center for Education Statistics and Claremont McKenna College Undergraduate Admissions Office.

Gender Discrimination A Woman s Opinion And Voice

In a male dominated society, it is challenging for a woman’s opinion and voice to be heard, and easy for gender inequality to thrive. Women have succeeded a great amount when it comes to comparison of how they were treated in the past, both in society and under the law, but the discrimination is still significant globally, even in areas such as Canada. Under the law, all individuals are the equivalent, regardless of one’s gender, race, or background, but in society women are still not treated with the same respect as males. Regardless, of what the law or the Supreme Court of Canada states, women are still accustomed to gender discrimination in the places they work and must deal with it against their coworkers. Unfortunately, it doesn’t†¦show more content†¦In 2012, an employee experienced extreme discrimination due to her gender while working under International Clothiers. Ms. Kohli had been working for International Clothiers and had â€Å"twice been passed over for promotion to Assistant Manager position because she was a woman† (Laird, HRLSC Cases). Ms. Kohli questioned her manager as to why men are considered as more fit for the job rather than women, but this only resulted in Mr.Bajwa reducing her work hours drastically and treating her unfairly. The victim chose to take further action and report it to the district manager in hopes of seeking help, but was left disappointed when he did not look into this matter further, but rather dismissed it. The fact that the managers at this store did not give Ms. Kohli the opportunity to become a manager simply based on her gender, is not only discriminating to her as a woman, but also devaluing her capability and worth. Stating that a woman is not fit for a job of a higher ranking, compared to men before even giving her the opportunity -simply because of her gender- is a clear violation of the law. Another way that women face discrimination in Canada is the significant wage gap b etween men and women. A 2-year long study that was conducted by the students of McMaster University in Hamilton, Ontario proved that â€Å"the average annual salary difference is

Essay on Random Drug Testing is a Waste of Time - 1623 Words

Her grades fell. She was always tired. She never seemed to be able to focus at school. Classes she used to be interested in became utterly mundane. Friends she used to care about became replaceable. She stopped spending time with her family. She sat on the bench at every soccer game instead of becoming the star player her coaches thought she could. This is what addiction to drugs can do to a young person’s life. Addiction can take away everything that once made that young person happy. The only thing that matters anymore is the drug, getting high, and getting higher. It is a horrible and tragic thing that destroys so many young lives. Some people think that in order to prevent these situations, the best solution is random drug testing.†¦show more content†¦These kids need to hear firsthand, from recovering addicts, the details of their struggles. They need to hear what it is like to be on the very brink of death, and how it feels to give up everything; house, car, fam ily, and friends, just to get high. They need to hear what a lonely place it is to be an addict. They need to know about the risks of trying a drug, even once, and how addiction can come from the first injection of heroin, a coma can be induced from the first dose of Ecstasy (Urban75 Drug Info). This is a much more powerful tool than making a half-hearted attempt at saving those who have already succumb to the pressures of adolescence, those already addicted, those who could have been saved years before if they had only received a good education on the matter. nbsp;nbsp;nbsp;nbsp;nbsp;People who are pro urinalysis also believe that with the threat of random drug testing, the population of students who decide to use drugs will be much smaller, because they Dwiggins 3 fear the consequences (Drug Testing in School Activities 2). The risk of being discovered might be enough to deter some young people from experimenting with drugs, but this small danger will not be enough to scare off a true addict. Those who are truly addicted are supposed to be the target for the most serious help. nbsp;nbsp;nbsp;nbsp;nbsp;IfShow MoreRelatedWelfare Drug Testing Essay1383 Words   |  6 PagesWelfare Drug Testing Trevor Brooks, SOC 110 11/09/2011 In today’s America, government aid is highly depended on. The US government has spent $498 billion dollars this year on welfare alone. The state of Tennessee has an average of 250,000 residents on welfare and has $3 billion dollars this year alone. To help cut costs and help tax payers, 36 states, including Tennessee, have proposed a bill to drug test all welfare recipients. Since the beginning of the year, the welfare rateRead MoreDrug Testing Essay1328 Words   |  6 PagesEven though drug testing is very expensive, ALL high school’s athletes should be tested because drugs are bad for your health and very addictive. A simple drug test could save many lives. Many schools around deny the request to drug test their athletes for the simple conclusion that the cost of the testing would just be to expensive. I disagree whole heartedly on that because although it may be expensive, we could save so many lives by requiring drug tests to play sports. Many students have l oveRead MoreWelfare Drug Testing Persuasive Speech1704 Words   |  7 Pageshousing. Currently there is mass debate, in courtrooms across the U.S., regarding the legality and morality of pre-assistance drug testing. This report is intended to familiarize the reader with the history of welfare reform; the histories of drug testing in regards to assistance eligibility; and persuade the audience to vote yes for mandatory pre-assistance drug testing. b) Body b.i) History of Welfare (b.i.1) The first welfare programs originated with the Social Security Act of 1935. (b.iRead MoreWelfare Drug Testing Should Not Be Allowed1416 Words   |  6 PagesPeople have been looking for a way to cut the costs of welfare for many years. And then Welfare drug testing was proposed. At initial thought it seemed like a grand idea and a great way to cut costs and to eliminate all the drug users in the system, and because of that welfare drug testing has been put into action in 13 states. But, welfare drug testing is completely ineffective. Welfare drug testing should not be allowed because it violates the rights of the welfare recipients, it is stereotypingRead MoreThe Effects Of Drug Testing On The Workplace1540 Words   |  7 Pagesinterview for a job, received a call that they were hired, and then heard their future employer say that they will have to do a drug test before they can start this new job? â€Å"Although many people think that illegal drugs such as marijuana, heroin, cocaine and other street drugs became a problem for youth in the 1960’s the truth of the matter is that there has always been a drug problem in the United States when it comes to substance abuse†(testcountry.org). This past summer I had an interview at RusselRead MoreDrug Testing For High Schools And Middle Schools1301 Words   |  6 PagesPersuading kids to not do drugs is a tough subject to approach as parents and teachers. When it comes to kids being unhappy, they will more than likely hear that drugs bring happiness to them. With drug testing involved in high schools and middle schools. The students should see that it is no longer an option to do drugs in order for their own self happiness. Students can result to other options that are more acceptable to society, and not to mention activities that are legal. Although these kidsRead More Performance Enhancing Drugs Essay2287 Words   |  10 Pagessupporting fans if they waste everything away on drugs. They have people who look up to them as role models and they get paid to perform. The sport is their life and also supports others. Non-professional athletes are not held to this standard however and should be allowed to do as they please. Although some drugs can be seen as damaging to the health of individuals, especially athletes, some drugs can be used in other ways. However the main problem of drugs isn’t the use of the drug but the abuse. PeopleRead MoreEssay about Half Brother by Holli Chang723 Words   |  3 Pages Characters: Ben - He is the main character, he is also the one telling the story about what happened to his family and Zan. At the beginning of the story, Ben didn’t want or like Zan. He thought he would take up too much of his time and be annoying. As the story progressed, he began to like Zan and they continued bonding together and eventually became best friends. As the story ended, Ben became the kind, loving person that got to keep and protect Zan. Richard Tomlin - He is the father whoRead MoreDrugs and Crime Midterm Essay1629 Words   |  7 Pages1.) Many drugs have been used for medical purposes at one time or another. Pick two drugs that have been utilized in this capacity and explain the medical rationale behind their use. Conclude your answer with a description of why each drug was later banned from medical usage. - Besides being an extremely addictive and dangerous narcotic, cocaine has some medicinal use. Cocaine has been used as a local anesthetic for eye and nasal surgery. Besides being an anesthetic, it also is a potent vasoconstrictorRead More Aviation Security Essay871 Words   |  4 Pages Airport Security around the world is an integral part of the modern times, the global web of people traveling for fun, business, adventure, and commodities are a way of life for many. Goods that were once scarce, or not available in certain parts of the world, merely twenty years ago for the general population are now easily attainable. Businesses are known to have meetings take place in various locations worldwide for their representatives. With all this moving of people from around the world who

Output of Channel Is Disposed To Errorâ€Free Samples for Students

Question: How to the Output of Channel Is Disposed To Error? Answer: Introduction Error Control Coding is required in case if we have noisy Channel, output of channel is disposed to error. For this we are essential to extent to guarantee bit stream correctness for transmitted Error control. The aim of coding at emerging coding methods to form the precision of the transmitted bit stream. Exemplification bit stream formed for this symbol is known as symbols codeword. The aim of Error control coding is to produce coding methods in order to check for the transmitted bit stream correctness. The symbol representation of bit stream is known as the symbols codeword The codes can be categorized in two parts mainly error Management codes and error detection codes. Error detection codes need to have transmit larger number of data bits as compared to the original data bits. We can discuss some category of these codes: Repetition codes This simplified and obvious solution to receive correct solution is to make repetition of the codes several times and combine them to get real message. This code with simplicity finds application in non AWAG and fading channels. Parity check codes This error detection technique has concept of using XOR of bits to set up a bit which indicates if we have even or odd number of 1s. the XOR sum have value 1 for odd parity and 0 for even parity. In case if there will be incorrect transmission of the bits then we will receive incorrect parity bits. CRC Cyclic redundancy check is for detection of the burst errors. Storage devices and digital networks finds application of this CRC. Error Correction techniques are divided in 2 parts: Forward Error Correction In this case if we have detected any error in transmission then receiver can correct the errors by its own and no need to ask for copy of data. Popular example of this is telephone applications Backward Error Correction In this case if we have detected any error in transmission then receiver can ask for another copy of data through back channel. Popular example of this is ARQ. In this we cannot request to repeat the data from back channel so this comes under forward error correction. In this case while ARQ discovers the error in transmission The Various mechanisms for error control are: Convolution Codes Repetition Codes Linear Block Codes In case of the block code entire set of code words possess similar length, and we can statically define the encoding for all likely data message. In case of convolution code the set of code word created be contingent on together the provided data message themself and a agreed count of formerly messages which are encoded: the state of encoder is variable and dependent on the processing of each message treated. The code words length is typically remains constant. We could additional differentiate amid [1] Linear codes Cyclic codes Systematic codes Description Cyclic and Linear block codes are the greatest usually utilized codes in protocols of data communication. In case of the linear code each combination of linear effective code words (for instance a given MOD 2 sum) creates additional effective code word. A given cyclic code defines as in that each effective code word cyclic shift also creates a effective code word which can be independently used in message encoding [2]. A given systematic code, lastly defined as the encoding in which all code word comprises the original signal data bits in unchanged form, whichever headed or followed through a distinct check bits group. In altogether scenarios the length of code words is more as compared to the data words. In case the original bits number can be given by d and the additional bits number is e, then the ratio of d /(d + e) can be classified as the code rate [3]. Syndrome Decoding Let original codeword be defined as c transmitted and received codeword be defined r = c + e, In which e defines the value designated for the error vector. The R (receiver symbol) Decoding (n k) A 1 matrix known as the matrix for error syndrome. It is calculated as follows Application Many application of coding theory was absorbed given efficiency less spectral, or limited in power, share capacity curve of the Shannons limit. This was mainly because of two issues. Sure of the purposes behind the expanding uses of coding are outer : the expected fast development in satellite interchanges; the insurgency in digital IC's; the expanding accentuation on the solid transmission of computerized information and of carefully coded analog signals; the accessibility of modest PCs for framework, simulation for hardwares, what's more Algorithms; the expanding modems digitalization, interconnections and switches, allowing prepared interfacing and regular viability; and the expanding modernity of the client group [6]. First numerous initial requests of coding were advanced for the NASA and the ESA satellite communication and deep-space systems, anywhere power was actual more and higher bandwidth. 1) The channel of deep-space is nearly precisely modeled like the AWGN memoryless channel that shaped the foundation for noisy channel over Shannons theorem. Therefore altogether the theoretic and simulation educations lead for this channel approved over nearly precisely into practice. 2) Edge decoders are directly finding broad application for the insurance of satellite connections in the Spade framework the constrained accessibility of the valuable radio range and a comparable spatial restriction on the quantity of satellites that could be set in stationary circle without shared obstruction requires examination from numerous headings [7]-[8]. 3) The utilization of decoding mainly Viterbi to decrease intersymbol impedance, in spite of the fact that effectively beneficial, may provide more here and additionally on phone channels, especially if mix with error correction could be accomplished. Comprehension of the different access of a restricted volume with space, recurrence, what's more, time measurements is as yet inadequate, especially when different commonsense constraints and the requirement for system control, exchanging, and request get to are incorporated. Promote comprehension and elaboration of such channel models as the communicate channel and the different access channel are required. The potential for huge changes in communication in view of source coding are most likely more noteworthy than for whatever other range, yet once more, the correct mix of workmanship, designing, what's more, hypothesis by and by getaways us. At long last, considering the present worry with protection and security, and the view that such issues will increment fundamentally as correspondence administrations and information storehouses develop, data scholars ought to consider an arrival full hover to issues that initially involved Shannon. The making and figuring out of codes secure against changed levels of endeavors could interest and involve us inconclusively. Deep Space Application One of the application of thee error control coding comes in deep space communication. Here we have communication channels with low power, here we have application for convolution codes with the Viterbi decoding. The utilization of the concatenation of convolution code and Reed-Solomon code was done to send volume of data in space. Storage media ECCs is widely utilized as a part of storage. Reed-Solomon and BCH codes are utilized as a part of utilizations like smaller disc players, circle drives, DVDs, 2D scanner tags and NAND streak drives. LDPC codes are supposed as the decision of ECC for SSDs and wellspring codes are deletion codes utilized as a part of datastorage utilization. A commonplace sound CD can have storage up to music of 69 minutes. Indeed, it takes around bits of 1.5 million to speak to only one moment of music. These bits are spoken to through pits on the one side of the circle. The average length of pits is around one micron, and are spiral track reordering happens, that is around width of 0.5 microns. In this case, scratches, clean and fingerprints gives mistakes that are wiped out by utilizing ECC. Conclusion For this we are essential to extent to guarantee bit stream correctness for transmitted Error control The aim of coding at emerging coding methods to form the precision of the transmitted bit stream. The exemplification bit stream of a given symbol is known as the symbols codeword. Error Control Coding is required in case if we have noisy Channel, output of channel is disposed to error. The aim of Error control coding is to produce coding methods in order to check for the transmitted bit stream correctness. The symbol representation of bit stream is known as the symbols code word In case of the block code entire set of code words possess similar length, and we can statically define the encoding for all likely data message. In case of convolution code the set of code word created be contingent on together the provided data message themself and a agreed count of formerly messages which are encoded: the state of encoder is variable and dependent on the processing of each message treated. The code words length is typically remains constant. Cyclic and Linear block codes are the greatest usually utilized codes in protocols of data communication. In case of the linear code each combination of linear effective code words (for instance a given MOD 2 sum) creates additional effective code word. References [1] C. E. Shannon, A mathematical theory of communication, Bell Syst. Tech. J., vol. 27, pp. 379423, 1948. [2] J. M. Wozencraft and I. M. Jacobs, Principles of Communication Engineering. New York: Wiley, 1965. [3] R. W. Hamming, Error detecting and error correcting codes, Bell Syst. Tech. J., vol. 29, pp. 147150, 1950. [4] I. M. Jacobs, Practical applications of coding, IEEE Trans. Inform. Theory, vol. IT-20, pp. 305310, May 1974. [5] G. D. Forney, Jr., and L. F. Wei, Multidimensional constellationsPart I: Introduction, figures of merit, and generalized cross constellations, IEEE J. Select. Areas Commun., vol. 7, pp. 877892, Aug. 1989. [6] J. L. Massey, Deep-space communication and coding: A marriage made in heaven, in Lecture Notes on Control and Information Sciences 82, J. Hagenauer, Ed.. Bonn, Germany: Springer-Verlag, 1992. [7] R. R. Green, A serial orthogonal decoder, in Jet Propulsion Laboratory Space Programs Summary, vol. IV, no. 3739, June 1966, pp. 247ndasDescriptionh;251. [8] J. M. Wozencraft and B. Reiffen, Sequential Decoding. Cambridge,MA: MIT Press, 1961. [9] R. M. Fano, A heuristic discussion of probabilistic decoding, IEEE Trans. Inform. Theory, vol. IT-9, pp. 6474, Apr. 1963. [10] S. Lin and H. Lyne, Some results on binary convolutional code generators, IEEE Trans. Inform. Theory, vol. IT-13, pp. 134139, Jan.1967 [11] J. L. Massey and D. J. Costello, Jr., Nonsystematic convolutional codes for sequential decoding in space applications, IEEE Trans. Commun. Technol., vol. COM-19, pp. 806813, Oct. 1971.