Book binding Essay Example for Free

Book binding Essay OBJECTIVES:2. OBJECTIVES:The term ‘binding’ is sometimes used to describe the cover of a book. For example, you might refer to a book as having a binding of leather, or being bound in linen. But binding also means the act of attaching many pages to one another to produce a book. Bookbinding is a very old craft and the techniques used in hand-binding have hardly changed over the centuries. Mechanization has changed the way most books are made but hand-bound books still use the same the techniques and equipment. As a craft, bookbinding plays an important role in the production of artists books, the preservation of antique books, and in training for fine arts students. As a commercial process, bookbinding plays a role in the lives of any consumer who picks up a book or magazine. Advances in commercial bookbinding techniques have greatly improved the cost, and therefore accessibility, of printed material all over the world. IT: 3. WHAT DID YOU DO TO ORGANIZE IT:A prior permission has been taken from the Teacher-in-Charge of our institution to perform the work. Eight students of class VIII, Sec A are selected to participate with me. The Biology Laboratory of this institution has been selected as the working place. I first told the students the procedure of book binding:†¢ Stapling and Sewing – The collected papers exactly the same sized are piled them up. Then staple down/sewed along one edge. †¢ Gluing A white paper paste, or library paste, is good for most purposes. †¢ Covering Any book will be enormously improved if it has some kind of a cover. The cover doesnt have to be cloth or cardboard or particularly heavy. [emailprotected] com 1 BOOK BINDING CONTRBUTIONS:4. CONTRBUTIONS:†¢ MINE – I directed as well as helped the students how to prepare for such works. †¢ MY HEAD TEACHER – He encouraged and motivated me to perform the work. He also helped me by inspiring the students also. He also helped me by granting a fund for that. †¢ MENTOR – The Principal, Prof. D. P. Nag Chowdhury of the College, Shimurali Sachinandan College of Education was the mentor who helped me mentally as well as providing printed materials to do the work. The Director of the workshop, Prof Trishna Goswami as well as the Coordinator, Prof. S. R. Adhikari of the College, Shimurali Sachinandan College of Education, P. O. – Shimurali, District – Nadia also helped me in many ways. A book binder of that locality also helped various ways to make successful this work. CTIVITY: 5. OUTPUT OF THE ACTIVITY:Students can bind books at home following these simple instructions. This is so simple that the students themselves can make them for the joy of learning science. It can encourage them in publishing business. PERSONAL:6. YOUR PERSONAL:†¢ OBSERVATIONS – Students shortlisted the materials from their book or as directed that are needed to perform the work. Sheets of paper for binding into a book, Bone folder, Studio Tac double-sided adhesive, Heavyweight papers for end pages, Pencil, Jade glue, Paint brush, Headband tape, Craft knife, Binders board (acid-free), Book canvas, Iron-on transfer paper (optional)are collected by the students from their homes and market. Then [emailprotected] com 2 BOOK BINDING they started the work following the book binding procedure as stated. My students enjoyed this very much and many of them tried this on their own. †¢ EXPERIENCES Teaching children about the publishing business entails more than writing stories and creating characters. In fact, you can turn any English lesson into a crafts project by introducing children to bookbinding activities. †¢ DIFFICULTIES Manipulatives and experiments are teaching aids that the children are allowed to play with and touch. Hence it was a time consuming process. FROM:7. FEED BACK FROM:†¢ STUDENTS The participants were fully satisfied and wished such programme to be of more and more so that they could update their knowledge activity. This is the spirit of teaching and learning. With hands on activities they acquire first-hand knowledge which inspires them to pursue the field of publishing to become successful who is the wealth of a nation. †¢ COLLEAGUES – They highly appreciated such activities more and more so that the students can easily understand their lessons. The students can test these works without any fear of cost or breakage. This is so simple that the students themselves can make them for the joy of learning science. Teaching children bookbinding is a way for them to become part of this long tradition of book arts in a fun and imaginative way. †¢ MENTOR – He thanked me so that I have done the work accordingly in involvement with my students in my institution. This will be proved very useful in rural and urban schools as well. ************* [emailprotected] com 3

Environmental impact of tourism in Romania

Environmental impact of tourism in Romania The Environmental Impact of Tourism in Romania Introduction In this essay the main attention will be focussed on the impact of tourism upon the environment in Romania, so the positive and the negative aspects of tourism will be brought in discussion. In Romania the environment is a factor influencing tourism demand. Given that the demand for products of interest is partly determined by its quality, the environment can have a positive or negative impact on tourism. Tourism-environment relationship is particularly important, protection and conservation of the environment being the primary condition for progress and development of tourism. This link is complex; it is manifested in both directions. The environment is defined as the quality of life of people living and natural environments suitable habitats for animals and plants. The impact of tourism on the environment The positive impact Tourism is one of the most important industries and has developed continuously. Romania is visited by more people which are interested in exploring new destinations and cultures as distant. Thus, areas having special natural resources attract more visitors, especially if they offer the opportunity to know the customs and traditions of other cultures. When tourism and environment coexist in harmony, environment benefits from tourism. There are many examples of this kind, most falling into one of two types: conservation and environmental rehabilitation. Preservation means keeping informed choice and use of the natural and anthropogenic. Conservation and tourism often go hand in hand. In Romania many historical and archaeological monuments have been saved from destruction because of tourist interest to them. In Romania parks and nature reserves managed to protect many species that would otherwise have been destroyed by uncontrolled hunting. Tourism not only provides a reason to preserve the environment from man, but also provides money for conservation: a share of the income from tourism can be used to preserve the environment. In this tourist from all over the world are involved in different touristic programs like hiking the trails of medium and high difficulty , visiting historical monuments and palaeontology, easy routes to points of Belvedere, and Keys resort to Rà ¢usor Buti, trails for ski touring, climbing routes, programs for the study / observation of flora, bird watching and observation traces animals. Conservation implies preservation of the environment in a form as close to the original, rehabilitation involves a major change in the use environment. Many buildings and tourist areas have been saved by being restored as tourist attractions or tourist accommodation.  Ã‚   Many buildings and tourist areas have been saved by being restored as tourist attractions or tourist accommodation. Many factories in Romania began a new life as museums, industrial areas were converted into places of festivals, a variety of impressive castles and houses that were in decay became accommodation for tourists. Such examples show how the environment can benefit from tourism, saving what would otherwise be lost entirely. The most important natural reserve from Romania, natural monument, internationally recognized as a Biosphere Reserve is Retezat National Park. The park contains many touristic attractions such as over 80 lakes, 20 peaks over 2000m, the most extensive and deepest glacial lake in Romania, more than 54 habitats of rare or vulnerable plants and animals, glacial relief in the north and caustic terrain in the south. In this reservation tourist from all over the world are involved in different touristic programs like hiking the trails of medium and high difficulty , visiting historical and paleontological monuments, light trails to points of Belvedere, ski at Rà ¢usor and Cheile Butii, climbing routes, programs for the study and observation of flora, bird watching and observation animal trails. Another international known touristic attraction from Romania is the Danube delta. Tourists from all over the world choose the Danube delta as their holyday destination because of its unique landscapes and habitats. This has a good impact upon the natural reservation, because foreign tourists help raising the money for modernising and maintaining the many and diverse natural habitats in the delta. The negative impact Tourism is a consumer of space and tourist resources, participating default degradation and environmental pollution and tourism potential. This degradation is carried out either by direct pressure of tourists on the landscape, flora and fauna and other tourist attractions on which tourism can partially or totally damaged or recovery by the misconception of some areas, points and tourist attractions. Human pressure on the natural environment increases day by day, people moving more often and longer distances on the past. Leisure offers greater opportunity in the exploitation and conquest of the natural environment, most free time is spent outside the city, in nature. Periodic output of the city to green areas in the form of tours, a weekend or holiday sites has become a social custom with negative environmental effects. Many of the environmental damage caused by tourism are caused by the large number of visitors arriving at destinations whose optimal reception capacity has been exce eded.   Ã‚   Environment rarely escape harm when the number of tourists is very high. Air and water quality and diversity of flora and fauna are inevitably affected in some way, and landscapes, cities and monuments. Movement of uncontrolled tourist sightseeing done in natural or anthropogenic causes of often irreversible destruction of some of the items they have devoted to tourist attractions (the destruction of vegetation and flora, breaking trees and especially juveniles, poaching, degradation of the landscape). Pollution is increasing and because of the nature of automobile tourism whose deleterious effect is alteration of air quality, destruction of grasslands, trees and flora, etc Another way of environmental degradation is the purpose of investment unscientific and irrational nature tourism, investments take the form of: over-dimensioning stations in terms of reception and treatment capacity, failure of general principles of natural resource exploitation. An example showing the mutual relationship between tourism and environmental complex in general, and the negative impact that it manifests on each other, in particular, is the disappearance of the last 20 years to 14 huts in the Romanian Carpathians, the loss due to fire. Such damage is due to negligence of tourists. Conclusions Through this essay it has been showen that tourism has much more negative impacts on the environment of Romania than positive ones and that they are often closely related to the economical aspect of tourism. In conclusion Romania is a country enjoying a natural setting with great potential and infrastructure often enough natural tourism, travel form, in this view, is less demanding . After research, results that Romania does not benefit by much more positive aspects, since many components of the environment have been destroyed by tourists, rather than preserved. As Romania has much to do about environmental preservation. References: Cooper et al, C., (1998) Tourism Principles and Practice, 2nd Edition. New York: Addison Wesley Longman Publishing Cooper et al, C., (2005) Tourism Principles and Practice, 3rd Edition. Harlow (Essex): Pearson Education Limited http://www.plural-magazine.com/article-the-danube-delta-eco-tourism-museum-center-in-tulcea.html http://www.romanianmonasteries.org/romania/retezat-national-park

Siddhartha Essay: Use of Form, Symbolism, and Conflict -- Hesse Siddha

Use of Form, Symbolism, and Conflict in Siddhartha  Ã‚        Ã‚  Ã‚  Ã‚  Ã‚   Hermann Hesse uses the literary devices of form, symbolism, and conflict to develop his novel, Siddhartha.    Hermann Hesse's novel, Siddhartha, "is a novel of classical symmetry, a perfection achieved" (Hermann Hesse 25).   It tells the story of a young man who sets out to find his true self.   Throughout his journey, Siddhartha converts to various religions, searching for the one religion that will help him discover his identity.   As his journey continues, the main character is forced to overcome various obstacles in pursuit of his true self.   He learns the ways of reality and its many flaws.   As the story progresses, he comes across a river inhabited by Vasudeva, the ferryman, who teaches Siddhartha to find the holy Om by listening to the river.   Finally, Siddhartha becomes satisfied with his newfound religion, which offers him his identity and his true happiness.      Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   Hesse employs a structured form throughout the novel, dividing the work into three sections, each section containing three chapters.   An interlude follows each section, signaling a change in the character's way of living (http://www.ic.ucsb.edu/~ggotts/hesse/works/jensid.html). This structure remains uniform throughout the entire novel, helping to establish its framework.      Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   In dividing his literary work into three sections of three chapters, Hesse uses each section to depict another new beginning in Siddhartha's continuing search for his life's meaning.   The first section deals with Siddhartha's Brahmin beliefs, and as the first section progresses, he continuously moves away from the Brahmin religion.   As a result, he makes a change, leading into the first sec... ...ngly impossible journey, thus discovering his true identity.    Works Cited: Freedman, Ralph. The Lyrical Novel.   Princeton, New Jersey: Princeton University Press, 1963 Hesse, Herman. Siddhartha. Dover Publications, 1998. Welch, Carolyn Roberts. Cliff's Notes on Hesse's Steppenwolf and Siddhartha. Lincoln, Nebraska: Cliff's Notes Inc., 1923.   Ziolkowski, Theodore. Hermann Hesse.   Columbia: Columbia University Press, 1966 Ziolkowski, Theodore. Hermann Hesse: A Study in Theme and Structure. Princeton: Princeton University Press, 1965.   Ziolkowski, Theodore. Hesse: A Collection of Critical Essays. Englewood Cliffs, New Jersey: Prentice-Hall, Inc., 1973   http://members.aol.com/_ht_a/jawaayu/hesse.html http://www.hermann-hesse.com/html/english/e.biographiw.html   http://http://www.ic.ucsb.edu/~ggotts/hesse/works/jensid.html

Cocultural Communication :: Essays Papers

Cocultural Communication A co-cultural experience When asked to write this paper about a co-cultural experience there was one that jumped right in to my mind. My experience occurred right around a year ago while I working for United Airlines. I worked out of the Canton-Akron Airport so the planes we flew were smaller then the jets out of Cleveland and were propeller planes. One day while checking in passengers like normal for our 5:50pm flight my co-cultural experience came up to the counter to check in. She was probably in her 30’s and was with two of her friends. She was on her way to Chicago to be a guest speaker at a large conference. There was a few things that made this woman unique to me from first sight. First of all she was in an electric wheelchair. Secondly this woman was overweight. Third she appeared to be slightly retarded judging by her actions. And lastly this woman had no arms and no legs. When I found out she was flying to Chicago and not her friends, I recommended that she fly out of Cleveland and that United Airlines would provide her with transportation up to the airport. The reason I recommended this is due to the fact that propeller planes do not have jet-ways that you walk or roll out in to the plane on. But rather propeller planes have approximately 8 or 9 narrow steps that people have to climb up to get in to the plane. For people with disabilities that could not walk up the steps we had a straight back chair to carry them up the steps with. The straight back chair involved a guy at the top of the chair and one at the bottom carrying the chair while walking up the steps. A woman of her size though would be very difficult to carry up the stairs and the fact that the steps are narrow could come in to play also. After my suggestion her friends were very disgusted with me and walked away upset I could tell. No less than a minute later I had a phone call from a represenative of the Americans with Disabilities Act telling me that it was discrimination what I was doing. I explained to him the situation with the steps and that in Cleveland she would be able to roll right onto the plane through a jet-way. Cocultural Communication :: Essays Papers Cocultural Communication A co-cultural experience When asked to write this paper about a co-cultural experience there was one that jumped right in to my mind. My experience occurred right around a year ago while I working for United Airlines. I worked out of the Canton-Akron Airport so the planes we flew were smaller then the jets out of Cleveland and were propeller planes. One day while checking in passengers like normal for our 5:50pm flight my co-cultural experience came up to the counter to check in. She was probably in her 30’s and was with two of her friends. She was on her way to Chicago to be a guest speaker at a large conference. There was a few things that made this woman unique to me from first sight. First of all she was in an electric wheelchair. Secondly this woman was overweight. Third she appeared to be slightly retarded judging by her actions. And lastly this woman had no arms and no legs. When I found out she was flying to Chicago and not her friends, I recommended that she fly out of Cleveland and that United Airlines would provide her with transportation up to the airport. The reason I recommended this is due to the fact that propeller planes do not have jet-ways that you walk or roll out in to the plane on. But rather propeller planes have approximately 8 or 9 narrow steps that people have to climb up to get in to the plane. For people with disabilities that could not walk up the steps we had a straight back chair to carry them up the steps with. The straight back chair involved a guy at the top of the chair and one at the bottom carrying the chair while walking up the steps. A woman of her size though would be very difficult to carry up the stairs and the fact that the steps are narrow could come in to play also. After my suggestion her friends were very disgusted with me and walked away upset I could tell. No less than a minute later I had a phone call from a represenative of the Americans with Disabilities Act telling me that it was discrimination what I was doing. I explained to him the situation with the steps and that in Cleveland she would be able to roll right onto the plane through a jet-way.

College Enrollment Essay

Income inequality has been increasing for the past 20 years. A substantial part of the increase in income differences can be explained by changes in the return to education. In dollar terms, 1973 college graduates earned 45 percent more than high school graduates; by 1994 they earned 65 percent more, based on real average hourly wages for college and high school graduates (Baumol and Blinder, 1997). The increasing income disparities between groups of differing educational attainment raises concern that access to postsecondary education (PSE) may not be as widespread as desired. President Clinton urged for the goal of universal college access in his 1997 State of the Union address, â€Å"We must make the thirteenth and fourteenth years of education—at least two years of college—just as universal in America by the 21st century as a high school education is today, and we must open the doors of college to all Americans. † Using data from the National Education Longitudinal Study of 1988 (NELS) and the National Postsecondary Student Aid Study (NPSAS), this study examines access to postsecondary education by individuals in different income and test score groups. While many studies have found a statistically significant effect of income on college enrollment,1 less attention has been paid to the effect of family income after controlling for student achievement. This study specifically addresses this issue. We also explore differences in the decision of whether or not to attend PSE or in the type of PSE attended. We are interested in whether students are substituting less expensive alternatives (such as public or 2-year institutions) for high cost institutions, or whether they are not attending PSE at all. However, we do not examine selectivity of institutions attended. Another goal of this study is to determine which factors, including high school experiences, are especially important in determining college enrollment patterns. Hossler and Maple (1993) find that information on individual background factors allows them to predict, with a high degree of accuracy, which ninth-graders will go to college. The emphasis in our study is on how 1 See, for example, Leslie and Brinkman (1987), Savoca (1990), Schwartz (1986), and Mortenson and Wu (1990). SECTION I. INTRODUCTION 1 MATHTECH, INC. early indicators, such as expectations and course-taking behavior in the eighth grade, are related to college attendance six years later. 2 Last, we explore whether financial aid availability is a critical factor in determining PSE attendance. The combined effects of shifting federal support from grants to loans, and college tuition increasing at a rate faster than inflation are expected to have a large impact on enrollment patterns for low income youth. This report examines knowledge of and attitudes toward financial aid, and the relationship between such factors and PSE attendance. We also examine the effect of financial aid receipt on PSE attendance. In summary, the main research questions addressed in this report are: 1. 2. 3. 4. What percentage of students attend PSE, and what types of PSE do they attend? How are income and test score related to who goes to college? What factors, including high school experiences, are especially important in determining college enrollment patterns? Is financial aid availability a critical factor for determining PSE attendance? The rest of the report proceeds as follows. Section II describes the literature on individual and institutional factors that affect PSE attendance. Section III provides an overview of the data used in this report. It describes the NELS data, the NPSAS data, samples and weights used in the study, and correction of standard errors for sampling techniques. Section IV examines who goes to college. The section highlights the main answers to the first two research questions posed above, in a univariate or multivariate framework. Section V examines factors related to PSE attendance. Section VI explores the importance of financial aid, including knowledge of financial aid, financial aid applications, and the relationship between being offered financial aid and PSE attendance. Last, we include a bibliography of cited references. The executive summary (at the beginning of the report) highlights our findings and provides policy implications. An NCES study, not yet released, has focused on the â€Å"pipeline to higher education† using the NELS data (NCES, 1997). SECTION I. INTRODUCTION 2 2 MATHTECH, INC. One subset of analysis for this study is the group of low income, high test score students. Low income, high test score students may have the potential to benefit greatly from PSE attendance and, therefore, we want to identify factors or constraints, particularly financial ones, that might limit the students’ educational opportunities beyond high school. SECTION I. INTRODUCTION 3 MATHTECH, INC. II. LITERATURE REVIEW Much of the research on college enrollment patterns is founded upon the â€Å"human capital† model Gary Becker advanced. According to this theory, one decides to enroll in college as an investment in future earning power. Individuals calculate the value of attending college by comparing costs (direct and indirect) with expected income gains, and they make the decision that will maximize their utility over the long term. To understand enrollment behavior according to this model, it is necessary to look at such factors as tuition levels, student financial aid, average wages for high school graduates, and the difference in lifetime earnings between high school and college graduates. Economists and others agree, however, that non-monetary factors also play a major part in the college enrollment decision. Sociologists’ models of status attainment have suggested a number of background variables that join with economic factors to influence college plans. These include both personal traits (e. g. , academic ability) and interpersonal factors, such as the level of encouragement a student receives from parents and teachers. Hossler and Maple (1993) suggest that individual decisions on enrollment can be broken down into three stages: predisposition, search, and choice. According to their research, students who will ultimately attend college can be differentiated from those who will not as early as the ninth grade. Within the econometric and sociological models outlined above, the factors affecting enrollment in college can be divided into two general types: those specific to individual students, such as academic achievement and parental education levels, and those specific to educational or vocational alternatives, such as college tuition, financial aid, and unemployment levels. Students’ enrollment decisions can be viewed as jointly determined by their individual characteristics and the institutional or societal conditions that prevail. We first review individual traits that affect college enrollment, and then institutional determinants. SECTION II. LITERATURE REVIEW 4 MATHTECH, INC. A. INDIVIDUAL FACTORS THAT AFFECT COLLEGE ENROLLMENT Several studies have used data from the National Longitudinal Study of the High School Class of 1972 (NLS72), the National Longitudinal Survey of Labor Market Experience, Youth Cohort (NLSY), and the High School and Beyond Survey (HSB) to examine the factors affecting college enrollments. Manski and Wise (1983), Rouse (1994), and a number of others have used the variables included in these data sets to estimate multinomial logit models of enrollment decisions. Among the researchers, there seems to be considerable agreement regarding the individual traits that help to determine enrollment. These traits are discussed below. Manski and Wise (1983) presented a key point, namely that the enrollment process begins with the student’s decision to apply to college. This is much more important than the decisions made by college admissions personnel, since most would-be college students are likely to be admitted to some postsecondary institution of average quality. Jackson (1988) reports that in 1972, more than 97 percent of college applicants were admitted to at least one of their top three choices. The factors of greatest interest, then, are those that cause the student to seek to enroll. Both Manski and Wise (1983) and Rouse (1994) find that individual traits such as achievement levels, high school class rank, and parental education levels are of primary importance in determining the likelihood of a student’s applying to college. They state that higher family income levels increase the probability of application as well, but to a lesser extent. Manski and Wise also cite a â€Å" ‘peer’ or high school quality effect,† such that the larger the share of a high school senior’s classmates who attend 4-year schools, the more likely he or she will be to do the same. A recent NCES report (1997) describes the relationship among six risk factors (such as changing schools two or more times) and PSE attendance rates. St. John and Noell (1989) and St. John (1990) draw similar conclusions from the NLS72 and HSB data sets. St. John and Noell state that certain â€Å"social background variables† appear to make college enrollment more likely. These include higher test scores, higher grades, higher SECTION II. LITERATURE REVIEW 5 MATHTECH, INC. maternal education levels,3 and family income, as cited by Manski and Wise and Rouse. Other key variables include participation in an academic track during high school and â€Å"high postsecondary aspirations,† as measured by students’ reporting of the highest level of schooling they expect to achieve. Hossler and Maple (1993) find that parental education levels have a stronger effect on enrollment plans than student ability or income level. Other background factors that researchers have found to be significant include the level of parental encouragement (Hossler, Braxton, and Coopersmith, 1989) and students’ own expectations about the college decision (Borus and Carpenter, 1984). Jackson (1988) concludes that test scores, grades, taking part in a college preparatory program, and attending a school with many college-going peers are the student attributes most important for college enrollment. Kohn, Manski, and Mundel (1976) report that parents’ education level has a positive effect on a student’s likelihood of enrollment, but state that this effect decreases as family income rises. A number of researchers have examined the effects of family income levels on college enrollment. Manski (1992:16) concludes that there are â€Å"persistent patterns of stratification of college enrollments by income. † Both Manski (1992) and Kane (1995) present census data for multi-year periods that show, for ascending income levels, a steadily increasing percentage of 18to 19-year-old dependent family members enrolled in college. Using the same data source, Clotfelter (1991) and Mortenson and Wu (1990) cite positive income effects for the 18- to 24year-old group as well. Hauser (1993) finds large family income effects on college enrollment for White and Hispanic families, but he finds no such effects for Black families. 3 St. John and Noell do not include paternal education levels as a variable in their study. Manski and Wise and Rouse consider maternal and paternal education levels as separate variables, but present their conclusions in terms of parental education levels as a whole. Most of the studies reviewed here do not distinguish between mother’s and father’s education levels. One exception is the study by Kohn, Manski and Mundel (1976). This study estimates a model using subsamples of the SCOPE survey from two different states. While one group shows that the father’s education level has a greater effect on the likelihood of college attendance than does the mother’s, the other group shows the mother’s education level as having a greater effect. SECTION II. LITERATURE REVIEW 6 MATHTECH, INC. B. INSTITUTIONAL FACTORS THAT AFFECT COLLEGE ENROLLMENT. In addition to the factors that operate at an individual level, researchers have found a variety of institutional factors, or factors pertaining to educational and vocational alternatives, that affect college enrollment levels. Manski and Wise (1983) include among these factors tuition level, â€Å"quality of school† (as measured by the average combined SAT score of incoming freshmen), and the availability of government and institutional financial aid. Rouse (1994) examines the factor of proximity by estimating changes in enrollments that would result from decreasing the average  distance to the nearest 2-year college. She also considers the effects of tuition levels and financial aid availability, as well unemployment rates, which serve as a measure of competing opportunities available to high school seniors. Tuition levels are another institutional factor with a significant effect on college enrollment. Leslie and Brinkman (1987) review 25 studies on this subject, and find a general consensus that a $100 increase in tuition nationwide, in 1982–1983 academic year dollars, would result in a 6 percent decline in the college participation rate for the 18- to 24-year-old group. Savoca (1990) makes the point that high tuition levels may lessen postsecondary enrollments in the aggregate by discouraging some students from ever applying to college. The effects of tuition levels are moderated in many cases by the effects of financial aid. McPherson and Schapiro (1991) state that the variable of interest should be net cost, or tuition less financial aid. At the initial stages of the enrollment decision, however, students often lack information on their eligibility for financial aid and the amount of aid they would be likely to receive. Researchers have differing views regarding the effects of financial aid on enrollment at different types of institutions. Reyes (1994) finds that increases in financial aid positively affect both 2-year and 4-year college enrollment rates, based on information from the NLSY and HSB. Manski and Wise (1983), using the NLS72, conclude that financial aid affects students’ decisions to attend 2-year institutions, as opposed to not going to college at all. However, this study finds that enrollments at 4-year schools have little sensitivity to the availability of financial aid. Manski and Wise do not consider the effect of financial aid on the student’s choice between a 2-year and a 4-year institution. SECTION II. LITERATURE REVIEW 7 MATHTECH, INC. Other researchers have compared the effects of decreasing tuition with the effects of increasing financial aid. Manski and Wise (1983) find that for those attending 2-year schools, an additional dollar of financial aid would be worth more than a one dollar reduction in tuition. St. John (1990:172) also finds that â€Å"college applicants†¦ [are] more responsive to changes in student aid than to changes in tuition,† except for those in the upper income group. Kane (1995), however, argues that while financial aid increases may be more equitable because they are means tested, they are not as effective as decreases in tuition. This is a consequence of the complexity of the financial aid application process and the unwillingness of low income families to borrow to finance a college education. When studying the effect of tuition and financial aid on PSE enrollment, the group to be especially concerned about is low income students. Leslie and Brinkman (1987) and Savoca (1990) find that tuition levels affect enrollment decisions for low income students much more than for middle and upper income groups. By the same token, the availability of financial aid is a much more crucial factor for those at lower income levels. Orfield (1992) notes that the maximum Pell grant is less than one-fifth of the tuition at an elite university. Such a gap between aid and costs, he contends, may steer many low income students toward lower cost schools. Hearn’s 1991 study supports this hypothesis. He finds that when academic ability, achievement, and other factors are controlled for, lower income students are especially likely to choose institutions of lower selectivity. Schwartz (1985) finds that low income students are affected differently by publicly provided financial aid and aid supplied by institutions. He states that public grants tend to promote greater equity among income groups in college enrollment. Private grants, however, are often awarded on the basis of academic ability, and they tend to favor students who could afford to go to college without them. Clotfelter (1991) expresses the same concern about the effects of institutional aid. Manski and Wise (1983) note that even public aid is not always awarded where the need is greatest. They state that in 1979, 59 percent of Basic Educational Opportunity Grants were awarded to students who would probably have gone to college in the absence of such aid. Table 1 summarizes the data sources used in the studies mentioned here. SECTION II. LITERATURE REVIEW 8 MATHTECH, INC. Table 1 MAIN DATA SOURCES FOR WORKS CITED IN LITERATURE REVIEW STUDY Borus, Michael E.and Carpenter, Susan A. , â€Å"Factors Associated with College Attendance of High-School Seniors† (1984) Clotfelter, Charles T. , â€Å"Demand for Undergraduate Education† (1991) Hauser, Robert M. , â€Å"Trends in College Entry among Whites, Blacks, and Hispanics† (1993) Hearn, James C. , â€Å"Academic and Nonacademic Influences on the College Destinations of 1980 High School Graduates† (1991) Hossler, Don, Braxton, John and Coopersmith, Georgia, â€Å"Understanding College Choice† (1989). Hossler, Don and Maple, Sue, â€Å"Being Undecided about Postsecondary Education† (1993) Jackson, Gregory A., â€Å"Did College Choice Change during the Seventies? † (1988) Kane, Thomas, â€Å"Rising Public College Tuition and College Entry: How Well Do Public Subsidies Promote Access to College? † (1995) Kohn, Meir G. , Manski, Charles F. , and Mundel, David S. , â€Å"An Empirical Investigation of Factors which Influence College-going Behavior† (1976) Leslie, Larry L. , and Brinkman, Paul T. , â€Å"Student Price Response in Higher Education† (1987) Manski, Charles F. , and Wise, David A. , College Choice in America (1983) Manski, Charles F. , â€Å"Income and Higher Education† (1992) McPherson, Michael S., and Schapiro, Morton Owen, â€Å"Does Student Aid Affect College Enrollment? New Evidence on a Persistent Controversy† (1991) Mortenson, Thomas G. , and Wu, Zhijun, â€Å"High School Graduation and College Participation of Young Adults by Family Income Backgrounds 1970 to 1989† (1990) National Center for Education Statistics. â€Å"Confronting the Odds: Students At Risk and the Pipeline to Higher Education† (1997). MAIN DATA SOURCES 1979 and 1980 National Longitudinal Surveys of Labor Market Experience, Youth Cohort (NLSY) Review of studies done by others, with data from Current Population Survey (CPS) and High. School and Beyond (HSB) CPS HSB, Higher Education Research Institute (HERI) data Review of studies done by others Cluster sample of 5,000 Indiana ninth graders National Longitudinal Study of the High School Class of 1972 (NLS72), HSB NLSY, HSB, CPS School to College: Opportunities for Postsecondary Education (SCOPE) Survey Meta-analysis of studies done by others NLS72 NLS72, HSB, CPS Cooperative Institutional Research Program (CIRP) data, CPS HSB, Current Population Report, CPS NELS SECTION II. LITERATURE REVIEW. 9 MATHTECH, INC. STUDY Orfield, Gary, â€Å"Money, Equity, and College Access† (1992) Reyes, Suzanne, â€Å"The College Enrollment Decision: The Role of the Guaranteed Student Loan† (1994) Rouse, Cecilia Elena, â€Å"What to Do after High School: The Two-Year versus Four-Year College Enrollment Decision† (1994) St. John, Edward P. , and Noell, Jay, â€Å"The Effects of Student Financial Aid on Access to Higher Education: An Analysis of Progress with Special Consideration of Minority Enrollment† (1989) St. John, Edward P., â€Å"Price Response in Enrollment Decisions: An Analysis of the High School and Beyond Sophomore Cohort† (1990) Savoca, Elizabeth, â€Å"Another Look at the Demand for Higher Education: Measuring the Price Sensitivity of the Decision to Apply to College† (1990) Schwartz, J. Brad, â€Å"Student Financial Aid and the College Enrollment Decision: The Effects of Public and Private Grants and Interest Subsidies† (1985) Schwartz, J. Brad, â€Å"Wealth Neutrality in Higher Education: The Effects of Student Grants† (1986) MAIN DATA SOURCES Review of history of federal student financial aid programs NLSY, HSB NLSY, HSB, CPS. NLS72, HSB HSB NLS72 HSB, CPS HSB, CPS SECTION II. LITERATURE REVIEW 10 MATHTECH, INC. III. DATA A. NELS DATA While a number of studies have used data from the National Longitudinal Survey, Youth Cohort (NLSY), the National Longitudinal Study of the High School Class of 1972 (NLS72), and the High School and Beyond Survey (HSB) to examine the factors affecting college enrollments, this work effort is among the first to use NELS to analyze these types of issues. In 1988, NELS initially surveyed over 24,000 public and private school eighth graders throughout the United States. The nationally representative eighth grade cohort was tested in four subjects (mathematics, reading, science, and social studies). Two teachers of each student (representing two of the four subjects) were also surveyed, as was an administrator from each school. On average, each of the 1,052 participating schools was represented by 24 students and five teachers. Parents were also surveyed, providing researchers with detailed information on family background variables. Since 1988, the initial eighth grade cohort has been re-surveyed three times (and has been â€Å"freshened† with new sample members). The first follow-up of NELS (spring, 1990), included the same components as the base year study, with the exception of the parent survey, which was not implemented in the 1990 round. It also included a component on early dropouts (those who left school between the end of eighth grade and the end of 10th grade). The second follow-up (spring, 1992), repeated all components of the first follow-up study and also included a parent questionnaire. However, this time only one teacher of each student (either a mathematics or a science teacher) was asked to complete a teacher questionnaire. High school transcript data were also collected for these students. A subsample of the NELS:88 second follow-up sample was again followed-up in the spring of 1994, when most sample members had been out of high school for 2 years. In all, 14,915 students were surveyed, most through computer-assisted telephone interviewing. Major content areas for the third follow-up questionnaire were: education histories; work experience histories; work-related training; family formation; opinions and other experiences; occurrence or SECTION III. DATA 11 MATHTECH, INC. non-occurrence of significant life events; and income. Data collection for this wave began on February 4, and ended on August 13, 1994. At the time the data were collected, most of the respondents were 2 years out of high school. Table 2 summarizes the components of the different waves of the surveys. Table 2 OVERVIEW OF NELS NELS Components Grades included Cohort Base Year Spring term 1988 grade 8 students: questionnaire, tests questionnaire questionnaire two teachers per student (taken from reading, mathematics, science, or social studies) First Follow-up Spring term 1990 modal grade = sophomore students, dropouts: questionnaire, tests none questionnaire two teachers per student (taken from reading, mathematics, science, or social studies) Second Follow-up Spring term 1992 modal grade = senior students, dropouts: questionnaire, tests, H. S.  transcripts questionnaire questionnaire one teacher per student (taken from mathematics or science). Third Follow-up Spring 1994 H. S. + 2 years all individuals: questionnaire none none none Parents Principals Teachers B. NPSAS DATA Because the NELS database does not contain detailed information on financial aid, the National Postsecondary Student Aid Study (NPSAS) database is used to supplement our study with additional financial aid information. This database is used to predict financial aid for the respondents in NELS based on demographic and other characteristics that are available in both databases. NPSAS is constructed specifically to provide information on financing of postsecondary education, so it is a good candidate for this use. This database surveys a nationally representative sample of undergraduate, graduate, and first-professional students attending less than 2-year, 2-year, 4-year, and doctoral granting institutions. Both students who receive and those who do not receive financial aid are surveyed. SECTION III. DATA 12 MATHTECH, INC. The 1993 NPSAS study collected information on more than 78,000 undergraduate and graduate students at about 1,100 institutions. To be eligible, students must have been enrolled between May 1, 1992 and April 30, 1993 at a postsecondary institution in the United States or Puerto Rico. The students had to be enrolled in courses for credit, and in a program of 3 months or longer. Also eligible for inclusion were students who received a bachelor’s degree between July 1, 1992 and June 30, 1993. Students who were enrolled in a GED program or who were also enrolled in high school were not included. C. SAMPLE AND WEIGHTS Of the 14,915 respondents in the third NELS follow-up, 13,120 are represented in all four waves of the NELS data. The remaining 1,795 respondents are either first follow-up â€Å"freshened† students,4 second follow-up freshened students,5 base-year ineligibles,6 or base-year eligible students who declined to participate in one or more of the survey waves, but who did participate in the third survey wave. The breakdown of these 1,795 respondents is as follows: 501 first follow-up freshened students, 102 second follow-up freshened students, 271 base-year ineligibles, and 921 base-year eligibles with missing survey waves. To take advantage of the longitudinal nature of the NELS data and to be consistent across models and issues in the report, we focus our work on the sample of 13,120 respondents represented in all four waves of the NELS data. Consequently, the weight used in our analyses, (â€Å"F3PNLWT†) applies to sample members who completed questionnaires in all four rounds of NELS:88. As a result, the longitudinal analyses that we conduct, and the estimates that are produced in this study can only be used to make projections to the population of spring 1988 eighth graders. In the descriptive tables, all percentages are weighted using F3PNLWT, including the analyses with the high school transcript data. Those who were tenth graders in 1990 but were not in the base-year sampling frame, either because they were not in the country or because they were not in the eighth grade in the spring term of 1988. Those who were 12th graders in 1992 but were not in either the base year or first follow-up sampling frames, either because they were not in the country or because they were not in the eighth (10th) grade in the spring term of 1988 (1990). 6 5 4 Students excluded in 1988 due to linguistic, mental, or physical obstacles to participation. 13 SECTION III. DATA MATHTECH, INC. This sample includes dropouts, since the purpose of this study is to examine the overall question of what characteristics of eighth graders in 1988 are related to PSE attendance. We focus on early indicators, such as educational expectations and course-taking behavior in the eighth grade, and not on the â€Å"pipeline† of high school experiences that a dropout would lack access to. However, the dropouts were not asked the same set of survey questions as the other respondents, and, therefore, some of the analysis does not include dropouts. For each of our tables or figures, we note whether or not the dropouts are included in the analysis. D. CORRECTED STANDARD ERRORS Because NELS data are collected through a multi-stage sampling scheme, calculation of standard errors through standard methods can understate these errors. The sampling technique used in NELS is a selection of schools, and then within schools, a selection of students. With this sampling method, the observations of different students may not be independent from one another. Stataâ„ ¢, the statistical software used for analysis in this report, corrects the standard errors for these sampling techniques. Except for multinomial logit models, for which this correction is not available, survey correction techniques are used, and we note whenever the corrections are not used. However, we have found that such corrections do not have a large effect on our results, and therefore, we present all results with confidence. E. VARIABLE DEFINITIONS. The appendix to this study contains definitions of the key variables used in our analysis. For each key variable, we describe how we constructed the variable and we list the names of the NELS variables used in the construction. SECTION III. DATA 14 MATHTECH, INC. IV. WHO GOES TO COLLEGE? A. WHAT PROPORTION OF STUDENTS ATTEND COLLEGE, AND WHAT TYPE OF COLLEGE DID THEY ATTEND? We begin our analysis by examining the demographics of postsecondary school choice and discussing our main findings regarding college attendance rates and types of postsecondary education (PSE) attended. As shown in Table 3, a majority of 1988 eighth graders attend some type of PSE by 1994. Overall, 62. 7 percent of the respondents attend PSE. (Note that in all of the tables in this report, all percentages are weighted. ) Students are most likely to attend a 4-year public or a less than 4-year public school. Approximately 24 percent of the students attend each of these types of schools. Next most common are 4-year private schools. Just over 11 percent of the respondents attend 4-year private schools. Only 4 percent of the respondents attend less than 4-year private schools. Thirty-seven percent of the respondents do not attend any type of PSE. Women are slightly more likely than men to attend PSE. While 60 percent of men attend PSE, 65 percent of women attend. Women are more likely than men to attend 4-year private schools and less than 4-year private schools. Native Americans, Blacks, and Hispanics are least likely to attend PSE and Asians and Pacific Islanders are most likely to attend PSE. Hispanics are most likely to attend less than 4year private schools. Students whose parents have higher education levels are much more likely to attend PSE. While only 33 percent of students whose parents have less than a high school education attend PSE, 90 percent of students whose parents have an advanced degree attend PSE. SECTION IV. WHO GOES TO COLLEGE? 15 MATHTECH, INC. Table 3 DEMOGRAPHICS OF POSTSECONDARY SCHOOL CHOICE1 No PSE 4-Year Public 4-Year Private.

Fulcher of Chartes:Pope Urban’s Speech at Clermont Essay

8.4 Fulcher of Chartres, â€Å"Pope Urban II’s Speech at Clermont† As the crusades began, Christians gathered to hear the insightful speech given by Pope Urban II in which he was able take unruly knights and give them a common enemy to fight. The enemies were the Muslims and Turks who were attacking the Byzantine Empire and the Holy Land. Urban II’s speech gave insights to the knightly class who were engaging in warlike tendencies and encouraged them to help people in need. On November 27, 1095, Pope Urban II began his influential speech to the church officials and nobles who were in attendance. In the beginning of his speech, Urban II said that he was given permission by God to come and speak to them about what was going on. The situations that were going on in the Christian society included the knightly class fighting each other, raping young women, robbing the churches, and other unseemly activities. Pope Urban II told them that in order to become â€Å"frien ds† with God, they would have to do things that were pleasing to God. These included leaving all matters that revolved around the church to the leaders of the church, and if they [the knights] were to rob the leaders of the church they will be cursed. At this point of his speech Pope Urban II is building up to the main reason for this call to order. Urban II informed his audience that the people of the Byzantine Empire were in need of their help, and it was their duty to help them. He explained to his listeners that the Turks and the Arabs have conquered the Byzantine Empire and taken over the Christian lands. Pope Urban II told the people that Christ commands them to help the Byzantine Empire regardless of their social class. â€Å"On this account I, or rather the Lord beseech you as Christ’s heralds† (358). Pope Urban II went on to say that whoever was to die in battle or die in any other kind of way, they would receive forgiveness for their sins. This is saying that no matter what they have done in the past, they would be forgiven for it all. Urban II continued to convince the people at his speech to help the Byzantine Empire defeat the Turks and Arabs and win back the Christian territory. This would lead to what is now called the First  Crusade. Crusade began in the fall of 1096 in Constantinople where crusaders gathered. The crusaders included the knights and people of Byzantine Empire. The Crusaders began to march through territories controlled by the Turks and Arabs which included Edessa and Antioch. They continued to head to Jerusalem in June 1099. The crusaders the n proceeded on a â€Å"five-week siege of Jerusalem† which fell in July of 1099. Crusaders then took over cities along the Mediterranean coast and built â€Å"fortified castle all over the Holy Land to protect their new territories† (Heilbrunn Timeline of Art History). The crusaders defeated the Egyptian relief army in August 1099. Pope Urban II died on July 29, 1099 and was not able to see the victory of reclaiming Jerusalem. Fulcher of Chartres clearly exemplified that he was bias towards Pope Urban II’s speech. Although he was there to hear the speech, he did not record the speech until years later. This proves that he truly believed in what Pope Urban II was protesting. Not only did Urban II’s speech help to reclaim the Christian lands, it also encouraged the knightly class and others listeners to reconnect with God’s laws and commandments. The First Crusades were not the ending of the battles, there was a second and third crusade. The crusaders failed in the second crusade, and had a dismal failure in the third crusade. These battles show that the Christian warriors had wanted to have what was rightfully Christ’s, and would not stop at any cost until they had it. Works Cited Chartres, Fulcher Of, trans. â€Å"Pope Urban II’s Speech at Clermont† p. 357-359 Mason, Ohio: Cengage Learning, 2012. Print. Department of Medieval Art and The Cloisters. â€Å"The Crusades (1095–1291)†. In Heilbrunn Timeline of Art History. New York: The Metropolitan Museum of Art, 2000–. http://www.metmuseum.org/toah/hd/crus/hd_crus.htm (October 2001)

Memory Organization

Memory Basics Memory is the workspace for the computers processor. It is a temporary storage area where the programs and data being operated on by the processor must reside. Memory storage is considered temporary because the data and programs will remain there only as long as the computer has electrical power or is not reset. Before being shut down or reset, any data that has been changed should be saved to a more permanent storage device of some type (usually a hard disk) so it can be reloaded into memory again in the future. We often call memory RAM, for Random Access Memory.Main memory is called RAM because you can randomly (and quickly) access any location in memory. When we talk about a computers memory, we usually mean the RAM in the system, meaning primarily the memory chips or modules that make up the primary active program and data storage used by the processor. This is often confused with the term storage, which should be used when referring to things such as disk and tape drives (although some people do consider them a form of memory). 2Types of Memory To better understand physical memory in a system, it is necessary to see where and how it fits into the system.Three main types of physical memory used in modern PCs are †¢ ROM: Read Only Memory †¢ DRAM: Dynamic Random Access Memory †¢ SRAM: Static RAM 2. 1ROM Read Only Memory, or ROM, is a type of memory that can permanently or semipermanently hold data. It is called read-only because it is either impossible or difficult to write to. ROM is also often referred to as non-volatile memory because any data stored in ROM will remain, even if the power is turned off. As such, ROM is an ideal place to put the PCs startup instructionsthat is, the software that boots the system.Note that ROM and RAM are not opposites, as some people seem to believe. In fact, ROM is technically a subset of the systems RAM. In other words, a portion of the systems Random Access Memory address space is mapped into one or more ROM chips. This is necessary to contain the software that enables the PC to boot up; otherwise, the proces- sor would have no program in memory to execute when it was powered on. For example, when a PC is turned on, the processor automatically jumps to address FFFF0h, expecting to find instructions to tell the processor what to do.This location is exactly 16 bytes from the end of the first megabyte of RAM space, and the end of the ROM. If this location was mapped into regular memory 1 chips, any data stored there would have disappeared when the power was turned off previously, and the processor would subsequently find no instructions to run the next time power was turned on. By placing a ROM chip at this address, a system startup program can be permanently loaded into the ROM and will be available every time the system is turned on. The motherboard ROM normally contains four main programs, including the following in most systems: †¢ POST: Power-On Self Test.A series of test routines that ensure the system components are operating properly. †¢ CMOS Setup: A menu-driven application that allows the user to set sys- tem configuration parameters, options, security settings, and preferences. †¢ Bootstrap Loader: The routine that first scans the floppy drive and then the hard disk, looking for an operating system to load. †¢ BIOS: Basic Input/Output System. A series of device driver programs designed to present a standard interface to the basic system hardware, especially hardware that must be active during the boot process. Four different types of ROM chips are ROM. Read Only Memory †¢ PROM. Programmable ROM †¢ EPROM. Erasable PROM †¢ EEPROM. Electrically Erasable PROM, also called a flash ROM No matter which type of ROM you use, the data stored in a ROM chip is non- volatile and will remain indefinitely unless intentionally erased or overwritten. 2. 1. 1PROM PROMs are a type of ROM that is blank when new and must be pr ogrammed with whatever data you want 2. 1. 2EPROM One variation of the PROM that has been very popular is the EPROM. An EPROM is a PROM that is erasable. EPROM is erased by exposure to intense UV light. 2. 1. 3 EEPROM/Flash ROMA newer type of ROM is the EEPROM, which stands for Electrically Erasable PROM. These chips are also called flash ROMs, and are characterized by their capability to be erased and reprogrammed directly in the circuit board in which they are installed, with no special equipment required. 2 2. 2DRAM Dynamic RAM is the type of memory chip used for most of the main memory in a modern PC. The main advantages of DRAM is that it is very dense, meaning you can pack a lot of bits into a very small chip, and it is very inexpensive, which makes it affordable for large amounts of memory.The memory cells in a DRAM chip are tiny capacitors that retain a charge to indicate a bit. The problem with DRAM is that it is dynamic, and because of the design must be constantly refresh ed or the electrical charges in the individual memory capacitors will drain and the data will be lost. Refresh occurs when the system memory controller takes a tiny break and accesses all the rows of data in the memory chips. DRAMs use only one transistor and capacitor pair per bit, which makes them very dense, offering a lot of memory capacity per chip than other types of memory. 2. 3 Cache MemorySRAMThere is another distinctly different type of memory that is significantly faster than most types of DRAM. SRAM stands for Static RAM, which is so named because it does not need the periodic refresh rates like DRAM (Dynamic RAM). Due to the design of SRAM, not only are refresh rates unnecessary, but SRAM is much faster than DRAM and is fully able to keep pace with modern processors. SRAM memory is available in access times of 2ns or less, which means it can keep pace with processors running 500MHz or faster! This is due to the SRAM design, which calls for a cluster of six transistors f or each bit of storage.The use of transistors but no capacitors means that refresh rates are not necessary because there are no capacitors to lose their charges over time. As long as there is power, SRAM will remember what is stored. Compared to DRAM, SRAM is much faster, but also much lower in density and much more expensive. The lower density means that SRAM chips are physically larger and store many less bits overall. The high number of transistors and the clustered design means that SRAM chips are both physically larger and much more expensive to produce than DRAM chips.Even though SRAM is too expensive for PC use as main memory, PC designers have found a way to use SRAM to dramatically improve PC performance. Rather than spend the money for all RAM to be SRAM memory, which can run fast enough to match the CPU, it is much more cost-effective to design in a small amount of high-speed SRAM memory, called cache memory. The cache runs at speeds close to or even equal to the processo r, and is the memory from which the processor normally directly reads from and writes to. During read operations, the data in the high-speed cache memory is resupplied from the lower-speed main memory or DRAM in advance. 3Memory Packaging Memory is made from tiny semiconductor chips and must be packaged into something less fragile and tiny in order to be integrated with the rest of the system Different types of memory paclages are †¢ Dual Inline Packages (DIPs) and Memory Modules †¢ Single Inline Memory Modules (SIMMs) †¢ Dual Inline Memory Modules (DIMMs) 3. 1DIPS Most memory chips are packaged into small plastic or ceramic packages called dual inline packages or DIPs. A DIP is a rectangular package with rows of pins running along its two longer edges These are the small black boxes you see on SIMMs, DIMMs or other larger packaging styles . 2SIMMs SIMMs are available in two flavors: 30 pin and 72 pin. 30-pin SIMMs are the older standard, and were popular on third and fourth generation motherboards. 72-pin SIMMs are used on fourth, fifth and sixth generation PCs. SIMMs are placed into special sockets on the motherboard created to hold them. The sockets are specifically designed to ensure that once inserted, the SIMM will be held in place tightly 3. 3DIMMs DIMMs are 168 pins in size, and provide memory 64 bits in width. They are a newer form factor and are becoming the de facto standard for new PCs; they are not used on older motherboards motherboards.SIMMs have contacts on either side of the circuit board but they are tied together. So a 30-pin SIMM has 30 contacts on each side of the circuit board, but each pair is connected. DIMMs however have different connections on each side of the circuit board 4Memory Banks Memory chips (DIPs, SIMMs, SIPPs, and DIMMs) are organized in banks on motherboards and memory cards. The banks usually correspond to the data bus capacity of the system’s microprocessor. The number of bits for each bank can be made up of single chips, SIMMs, or DIMMs. 4 5Memory ReliabilityA part of the nature of memory is that it will inevitably fail. These failures are usually classified as two basic types: hard fails and soft errors. The most well understood are hard fails, in which the chip is working and then, due to some flaw, physical damage, or other event, becomes damaged and experiences a permanent failure. Fixing this type of failure normally requires replacement of some part of the memory hardware, such as the chip, SIMM, or DIMM. Hard error rates are known as HERs. The other more insidious type of failure is the soft error.A soft error is a nonpermanent failure that may never reoccur, or occur at infrequent intervals. (Soft fails are effectively â€Å"fixed† by powering the system off and back on. ) Soft error rates are known as SERs. There are basically three levels and techniques for fault tolerance used in modern PCs: †¢ Non-parity †¢ Parity †¢ ECC (Error Correcting Co de) Non-parity systems have no fault tolerance at all. The reason they are even used is because they have the lowest inherent cost. No additional memory is necessary as is the case with parity or ECC techniques. 6ParityTne standard IBM set for the industry is that the memory chips in a bank of nine each handle one bit of data: eight bits per character plus one extra bit called the parity bit. As the eight individual bits in a byte are stored in memory, a parity genera- tor/checker, which is either part of the CPU or located in a special chip on the motherboard, evaluates the data bits by counting the number of 1s in the byte. If an even number of 1s is in the byte, the parity generator/checker creates a 1 and stores it as the ninth bit (parity bit) in the parity memory chip.That makes the total sum for all nine bits an odd number. If the original sum of the eight data bits is an odd number, the parity bit created is 0, keeping the 9-bit sum an odd number. The value of the parity bit is always chosen so that the sum of all nine bits (eight data bits plus one parity bit) is an odd number. The following examples may make it easier to understand: Data bit number: 0 1 2 3 4 5 6 7 Data bit value:10110011 Parity bit:0 5 In this example, because the total number of data bits with a value of 1 is an odd number (5), the parity bit must have a value of 0 to ensure an odd sum for all nine bits.The following is another example: Data bit number: 0 1 2 3 4 5 6 7 Data bit value :00110011 Parity bit: 1 In this example, because the total number of data bits with a value of 1 is an even number (4), the parity bit must have a value of 1 to create an odd sum for all nine bits. When the system reads memory back from storage, it checks the parity information. If a (9-bit) byte has an even number of bits with a parity bit value of 1, that byte must have an error. The system cannot tell which bit has changed, or if only a single bit has changed.If three bits changed, for example, the byte still flags a parity-check error; if two bits changed, however, the bad byte may pass unnoticed. The following examples show parity-check messages for three types of systems: For the IBM PC: PARITY CHECK x For the IBM XT: PARITY CHECK x yyyyy (z) For the IBM AT and late model XT: PARITY CHECK x yyyyy Where x is 1 or 2: 1=Erroroccurredonthemotherboard 2=Erroroccurredinanexpansionslot yyyyy represents a number from 00000 through FFFFF that indicates, in hexadecimal notation, the byte in which the error has occurred. Where (z) is (S) or (E ): S) = Parity error occurred in the system unit (E ) = Parity error occurred in the expansion chassis When a parity-check error is detected, the motherboard parity-checking cir- cuits generate a non-maskable interrupt (NMI), which halts processing and di- 6 verts the systems attention to the error. The NMI causes a routine in the ROM to be executed. The routine clears the screen and then displays a message in the upper-left corner of the screen . The message differs depending on the type of computer system. 7 ECC (Error Correcting Code) ECC goes a big step beyond simple parity error detection.Rather than just detecting an error, ECC allows a single bit error to be corrected, which means the system can continue on without interruption and without corrupting data. ECC as implemented in most PCs can only detect and not correct double-bit errors. Because studies have indicated that approximately 98 percent of memory errors are single- bit variety, the most commonly used type of ECC is one in which the attendant memory controller detects and corrects single-bit errors in an accessed data word (double-bit errors can be detected, but not corrected).This type of ECC is known as SEC-DED and requires an additional seven check bits over 32 bits in a 4-byte system and eight check bits in an 8-byte system. ECC in a 4-byte system obviously costs more than non-parity or parity, but in an 8-byte system, ECC and parity costs are equal. ECC entails the memory controller calculating the check bits on a memory- write operation, performing a compare between the read and calculated check- bits on a read operation and, if necessary, correcting bad bit(s).The additional ECC logic in the memory controller is not very significant in this age of inex- pensive, high-performance VLSI logic, but ECC actually affects memory perfor- mance on writes. This is because the operation must be timed to wait for the calculation of check bits and, when the system waits for corrected data, reads. On a partial-word write, the entire word must first be read, the affected byte(s) rewritten, and then new check bits calculated. This turns partial-word write operations into slower read-modify writes. Most memory errors are of a single-bit nature, which are correctable by ECC.Incorporating this fault-tolerant technique provides high system reliability and attendant availability. An ECC-based system is a good choice for servers, workstations, or mis sion-critical applications in which the cost of a potential memory error outweighs the additional memory and system cost to correct it, along with ensuring that it does not detract from system reliability. 8 The System Logical Memory Layout The original PC had a total of 1M of addressable memory, and the top 384K of that was reserved for use by the system.Placing this reserved space at the top (between 640K and 1024K instead of at the bottom, between 0K and 640K) led to what today is often called the conventional memory barrier. The constant pressures on system and peripheral manufacturers to maintain compatibility by never breaking from the original memory scheme of the first PC has resulted in 7 a system memory structure that is (to put it kindly) a mess. Logical memory sections are given below †¢ Conventional (Base) memory †¢ Upper Memory Area (UMA) †¢ High Memory Area (HMA) †¢ Extended memory (XMS) †¢ Expanded memory (obsolete) Video RAM memory (part of UMA) †¢ Adapter ROM and Special Purpose RAM (part of UMA) †¢ Motherboard ROM BIOS (part of UMA) 8. 1 Conventional (Base) Memory The original PC/XT-type system was designed to use 1M of memory workspace, sometimes called RAM (random access memory). This 1M of RAM is divided into several sections, some of which have special uses. DOS can read and write to the entire megabyte, but can manage the loading of programs only in the portion of RAM space called conventional memory, which was 512K at the time the first PC was introduced.The other 512K was reserved for use by the system, including the motherboard and adapter boards plugged into the system slots. After introducing the system, IBM decided that only 384K was needed for these reserved uses, and the company began marketing PCs with 640K of user memory. Thus, 640K became the standard for memory that can be used by DOS for running programs, and is often termed the 640K memory barrier. The remaining memory after 640K was rese rved for use by the graphics boards, other adapters, and the motherboard ROM BIOS.This barrier largely affects 16-bit software such as DOS and Windows 3. 1, and is much less of a factor with 32-bit software and operating systems such as Windows 95/98, NT, and so on. 8. 2 Upper Memory Area (UMA) The term Upper Memory Area (UMA) describes the reserved 384K at the top of the first megabyte of system memory on a PC/XT and the first megabyte on an AT-type system. This memory has the addresses from A0000 through FFFFF. The way the 384K of upper memory is used breaks down as follows: †¢ The first 128K after conventional memory is called video RAM.It is re- served for use by video adapters. When text and graphics are displayed onscreen, the electronic impulses that contain their images reside in this space. Video RAM is allotted the address range from A0000-BFFFF. 8 †¢ The next 128K is reserved for the adapter BIOS that resides in read-only memory chips on some adapter boards plug ged into the bus slots. Most VGA-compatible video adapters use the first 32K of this area for their onboard BIOS. The rest can be used by any other adapters installed. Many network adapters also use this area for special-purpose RAM called Shared Memory.Adapter ROM and special-purpose RAM is allotted the address range from C0000-DFFFF. †¢ The last 128K of memory is reserved for motherboard BIOS (the basic input/output system, which is stored in read-only RAM chips or ROM). The POST (Power-On Self Test) and bootstrap loader, which handles your system at bootup until the operating system takes over, also reside in this space. Most systems only use the last 64K (or less) of this space, leaving the first 64K or more free for remapping with memory managers. Some systems also include the CMOS Setup program in this area.The motherboard BIOS is allotted the address range from E0000-FFFFF. 8. 3Extended Memory The memory map on a system based on the 286 or higher processor can extend bey ond the 1M boundary that exists when the processor is in real mode. On a 286 or 386SX system, the extended memory limit is 16M; on a 386DX, 486, Pentium, Pentium MMX, or Pentium Pro system, the extended memory limit is 4G (4,096M). Systems based on the Pentium II processor have a limit of 64G (65,536M). For a system to address memory beyond the first megabyte, the processor must be in protected modethe native mode of 286 and higher processors.On a 286, only programs designed to run in protected mode can take advantage of extended memory. 386 and higher processors offer another mode, called virtual real mode, which enables extended memory to be, in effect, chopped into 1M pieces (each its own real-mode session). Virtual real mode also allows for several of these sessions to be running simultaneously in protected areas of memory. The extended memory specification (XMS) was developed in 1987 by Mi- crosoft, Intel, AST Corp. , and Lotus Development to specify how programs would use exte nded memory.The XMS specification functions on systems based on the 286 or higher and allows real-mode programs (those designed to run in DOS) to use extended memory and another block of memory usually out of the reach of DOS. Before XMS, there was no way to ensure cooperation between programs that switched the processor into protected mode and used extended memory. There was also no way for one program to know what another had been doing with the extended memory because none of them could see that memory while in real mode. HIMEM.SYS becomes an arbitrator of sorts that first grabs all the extended memory for itself and then doles it out to programs that know the XMS protocols. In this manner, several programs that use XMS memory can operate together under DOS on the same system, switching the pro- cessor into 9 and out of protected mode to access the memory. Extended memory can be made to conform to the XMS specification by installing a de- vice driver in the CONFIG. SYS file. The most common XMS driver is HIMEM. SYS, which is included with Windows 3. x and later versions of DOS, starting with 4. and up. 8. 4 High Memory Area (HMA) The High Memory Area (HMA) is an area of memory 16 bytes short of 64K in size, starting at the beginning of the first megabyte of extended memory. It can be used to load device drivers and memory-resident programs to free up conventional memory for use by real-mode programs. Only one device driver or memory-resident program can be loaded into HMA at one time, no matter what its size. Originally, this could be any program, but Microsoft decided that DOS could get there first, and built capability into DOS 5 and newer versions.The HMA area is extremely important to those who use DOS 5 or higher because these DOS versions can move their own kernel (about 45K of program instructions) into this area. This is accomplished simply by first loading an XMS driver (such as HIMEM. SYS) and adding the line DOS=HIGH to your CONFIG. SYS file. Tak ing advantage of this DOS capability frees another 45K or so of conventional memory for use by real-mode programs by essentially mov- ing 45K of program code into the first segment of extended memory.Although this memory was supposed to be accessible in protected mode only, it turns out that a defect in the design of the original 286 (which, fortunately, has been propagated forward to the more recent processors as a feature) accidentally al- lows access to most of the first segment of extended memory while still in real mode. The use of the HMA is controlled by the HIMEM. SYS or equivalent driver. The origins of this memory usage are interesting because they are based on a bug in the original 286 processor carried forward through even the Pentium II. 8. 5 Expanded MemorySome older programs can use a type of memory called Expanded Memory Spec- ification or EMS memory. Unlike conventional (the first megabyte) or extended (the second through 16th or 4,096th megabytes) memory, expanded memory is not directly addressable by the processor. Instead, it can only be accessed through a 64K window and small 16K pages established in the UMA. Expanded memory is a segment or bank-switching scheme in which a custom memory adapter has a large number of 64K segments onboard, com- bined with special switching and mapping hardware. The system uses a free segment in the UMA as the home address for the EMS board.After this 64K is filled with data, the board rotates the filled segment out and a new, empty segment appears to take its place. In this fashion, you have a board that can keep on rotating in new segments to be filled with data. Because only one segment can be seen or oper- ated on at one time, EMS is very inefficient for program code and is normally 10 only used for data. 9Video Memory The video memory is such an important component of the video card, and indirectly the entire PC, that several new memory technologies have been created specifically for it.The goal: to impr ove the speed with which information can be pumped into and out of the video memory, to keep system performance high as the video system tries to do more and more. Various memory technologies now being used on video cards are explained below. 9. 1 Standard (Fast Page Mode) DRAM The oldest technology used in video card memory, fast page mode (FPM) memory is now considered â€Å"standard† DRAM as it has the fewest performanceenhancing capabilities of the different types of memory on the market. FPM DRAM is a technology used primarily for main system memories (even there, it is now considered a poor performer) and is not really ell-suited for highperformance video applications. 11 FPM is the least expensive type of memory available for video, and is used today mostly on low-end or generic cards (as well as older cards of course). For many applications they can be quite satisfactory; however, they reach their limits quickly when trying to use high resolution modes, especially in true color. The limitations of standard DRAM are due to two primary effects: it is single ported (which means it can only do one access at a time) and it runs at a relatively low speed and access width. 9. 2 Extended Data Out (EDO) DRAMEDO DRAM is the same as standard FPM DRAM except for a slight modification in the access cycle that gives it a small performance boost. With EDO DRAM, one read to memory can begin before the last one has completely finished; this yields a raw speed improvement of between 5 and 20 percent, depending on whom you ask. Originally used only for main system memory, EDO DRAM is becoming more popular on video cards because it provides slightly improved performance over standard DRAM at the same cost. (At one time EDO was more expensive than FPM but due to supply and demand effects now, EDO is actually the same cost or lower).EDO is still, however, a low-cost and low-performance solution compared to other types of video memory, and is not used on high-end card s. 9. 3 Video RAM (VRAM) The traditional, standard DRAM used for video cards typically does not have enough bandwidth to handle the demands of running a card at high resolution and color depths, with acceptable refresh rates. The main reason why is the two competing access factors for the video memory: the processor writing new information to the memory, and the RAMDAC reading it many times per second in order to send video signals to the monitor.To address this fundamental limitation, a new type of memory was created called video RAM or VRAM. As the name implies, this memory is specifically tailored for use in video systems. The fundamental difference between VRAM and standard DRAM is that VRAM is dual-ported. This means that it has two access paths, and can be written to and read from simultaneously. The advantages of this are of course enormous given what the video card does: many times per second a new screen image is calculated and written to the memory, and many times per seco nd this memory is read and sent to the monitor.Dual- porting allows these operations to occur without bumping into each other. VRAM provides substantially more bandwidth than either standard DRAM or EDO DRAM; double in many cases. It is more suited for use in systems requiring high resolution and color depth displays. The only reason that it hasn’t replaced standard DRAM entirely is of course: cost. VRAM is more complex and requires more silicon per bit than standard DRAM, which makes it cost more. 12 9. 4Window RAM (WRAM)Window RAM or WRAM is a modification of regular VRAM that both improves performance and reduces cost on a bit-for-bit basis. Designed specifically for use in graphics cards, WRAM is also dual-ported but has about 25% more bandwidth than VRAM, and also incorporates additional features to allow for higher performance memory transfers for commonly used graphical operations such as text drawing and block fills. Furthermore, WRAM is less expensive than VRAM to ma nufacture (although still more expensive than DRAM). 9. 5 Synchronous Graphics RAM (SGRAM)A relatively newer RAM technology, Synchronous Graphics RAM or SGRAM tackles the poor performance of regular DRAM by increasing greatly the speed at which memory transfers take place. SGRAM also incorporates specific per- formance enhancing features designed to work with acceleration features built into video cards, to greatly improve overall video processing speed. SGRAM is still single-ported, unlike VRAM or WRAM, but offers performance that is much closer to VRAM than DRAM due to its advanced design. 10 Flash Memory DevicesFlash memory has been around for several years as a main or an auxiliary storage medium for notebook computers. However, the rise of devices such as digital cameras and MP3 players and the presence of USB ports on practically all recent systems have transformed this technology from a niche product into a mainstream must-have storage technology. Flash memory is a type of no nvolatile memory that is divided into blocks rather than bytes, as with normal RAM memory modules. Flash memory, which also is used in most recent computers for BIOS chips, is changed by a process known as Fowler-Nordheim tunneling.This process removes the charge from the floating gate associated with each memory cell. Flash memory then must be erased before it can be charged with new data. The speed, low reprogramming current requirements, and compact size of recent flash memory devices have made flash memory a perfect counterpart for portable devices such as notebook computers and digital cameras, which often refer to flash memory devices as so-called â€Å"digital film†. Unlike real film, digital film can be erased and reshot.Ultra-compact, USB-based keychain drives that use flash memory are replacing both traditional floppy drives and Zip/SuperDisk drives for transporting data between systems. Diiferent types of flash memory devices are expained below. 10. 1Compact Flash CompactFlash was developed by SanDisk Corporation in 1994 and uses ATA architecture to emulate a disk drive; a CompactFlash device attached to a com- 13 puter has a disk drive letter just like your other drives. Later types of flash memory also use ATA architecture, either implemented in the device itself or in its controller. 0. 2MultiMedia Card The MultiMediaCard (MMC) was codeveloped by SanDisk and Infineon Tech- nologies AG (formerly Siemens AG) in November 1997 for use with smart phones, MP3 players, digital cameras, and camcorders. The MMC uses a simple 7-pin serial interface to devices and contains low-voltage flash memory. 10. 3Secure Digital (SD) A SecureDigital (SD) storage device is about the same size as MMC , but it’s a more sophisticated product. SD, which was codeveloped by Toshiba, Matsushita Electric (Panasonic), and SanDisk in 1999, gets its name from two special features.The first is encrypted storage of data for additional security, meeting current and fut ure Secure Digital Music Initiative (SDMI) standards for portable devices. The second is a mechanical write-protection switch. 10. 4Pen Drive As an alternative to floppy and Zip/SuperDisk-class removable-media drives, USB-based flash memory devices are rapidly becoming the preferred way to move data between systems. The first successful drive of this type – Trek’s ThumbDrivewas – introduced in 2000 and has spawned many imitators, in- cluding many that incorporate a keychain or pocket clip to emphasize their portability.Unlike other types of flash memory, USB keychain drives don’t require a separate card reader; they can be plugged in to any USB port or hub. Al- though a driver is usually required for Windows 98 and Windows 98SE, most USB keychain drives can be read immediately by newer versions of Windows, particularly Windows XP. As with other types of flash memory, USB keychain drives are assigned a drive letter when connected to the computer. Most have capacities ranging from 128MB to 1GB, with some capacities as high as 2GB or more.However, typical read/write performance of USB 1. 1-compatible drives is about 1MBps. Hi-Speed USB keychain drives are much faster, providing read speeds ranging from 5MBps to 15MBps and write speeds ranging from 5MBps to 13MBps. 11Advanced Memory Technologies 11. 1RDRAM RDRAM is a proprietary technology made by Rambus Inc. for use exclusively in certain Intel compatible motherboards 14 RDRAM stands for Rambus Dynamic Random Access Memory. It can access data anywhere on the chip; It requires power to hold its data; and it transfers data twice per clock signal.However, it uses a smaller pathway, or â€Å"system bus,† to send information. The Rambus system bus is 16-bits wide. Rambus transfers data at 800 megahertz (MHz) and faster. Rambus is the more expensive type of memory since its proprietary, royalty costs that manufacturers must pay to produce it tend to result in higher retail prices. Add itionally, Rambus compatible motherboards require that all of their RAM slots be occupied. Traditionally, a computer may contain anywhere from one to four ram slots. If a slot is unoccupied, the system still operates.Rambus requires that either a Rambus memory module or a kind of place holder known as a continuity module be in place to complete the memory path to the bus. 11. 2 DDR SDRAM (DDR) Double data rate (DDR) SDRAM memory is a JEDEC-created standard that is an evolutionary upgrade of standard SDRAM in which data is transferred twice as quickly. Instead of doubling the actual clock rate, DDR memory achieves the doubling in performance by transferring twice per transfer cycle: once at the leading (falling) edge and once at the trailing (rising) edge of the cycle.This effectively doubles the transfer rate, even though the same overall clock and timing signals are used. Since its inception, manufacturers have release new and faster versions of DDR. These are based on the use of p refetch buffers that access not only the memory, or â€Å"dataword,† requested by the processor but also the datawords adjacent to it on the chip. Thus DDR2 â€Å"fetches† four datawords per memory access, double the amount of DDR. DDR3, a more recent update, obtains eight datawords per access. 15