Chuyển đổi tài liệu PDF sang Word 01:07' 22/11/2005 (GMT+7) Word đã trở thành "vua" của các bộ soạn thảo văn bản. Hầu hết các văn bản đều được định dạng và in bằng Word. Tuy nhiên, bạn có một số văn bản bằng PDF (Portable Document Format), bạn muốn chỉnh sửa các tài liệu này trước khi in ấn. Acrobat Reader không có khả năng chỉnh sửa văn bản, còn Acrobat thì giá cả hơi "mắc" mà lại đòi hỏi tài nguyên khá lớn. Vậy, có phần mềm nào có khả năng chuyển đổi định dạng từ PDF sang Word mà vẫn giữ nguyên định dạng, giá cả cũng chấp nhận được và lại tiêu tốn ít tài nguyên hệ thống ? Thực ra, để giữ nguyên các định dạng tài liệu sau khi chuyển đổi là rất phức tạp và khó khăn. Đến ngay như phần mềm Acrobat, khi chuyển đổi tập tin PDF sang Word cũng không được hoàn hảo. Tuy nhiên, nếu bạn đã từng sử dụng qua phần mềm SolidPDFConverter của hãng Solid, phần mềm này thật tuyệt vời ! Các tài liệu phức tạp gồm các nội dung văn bản, hình ảnh, bảng tính . vẫn giữ nguyên định dạng sau khi chuyển đổi sang Word. VietNamNet đã thử nghiệm chuyển đổi tài liệu phức tạp gồm hình ảnh, bảng biểu , đồ hoạ, văn bản xen kẽ, khoảng 70 trang bằng Adobe Acrobat và SolidDPFConverter. Kết quả là SolidPDFConverter cho tốc độ chuyển đổi tài liệu nhanh hơn và giữ được định dạng tài liệu gốc chính xác hơn Acrobat. Tuy nhiên khi chỉnh sửa một số văn bản kết hợp trong các bảng biểu, đồ hoạ cho kết quả chưa được tốt lắm. Mặc dù vậy SolidPDFConverter vẫn là công cụ đáng giá với mức giá tương đối rẻ so với phần mềm đồ sộ tương đối "nặng ký" Acrobat. SolidPDFConverter có đồ thuật đơn giản sẽ giúp bạn chuyển đổi định dạng .pdf sang định dạng .doc nhanh chóng chỉ với 5 bước: Bước 1: Chọn định dạng Bạn hãy chọn tập tin PDF cần chuyển đổi ngay trong khung tìm tài liệu của SolidPDFConverter. Hãy sử dụng tùy chọn: • Flowing: Với chế độ này, các trang vẫn giữ nguyên cách trình bày, định dạng, đồ họa và các dữ liệu văn bản. • Continuous: Với chế độ này cái mà bạn cần chỉ là nội dung chứ không cần chính xác cách trình bày của tài liệu. Ví dụ: giả sử mục đích là bạn cần nội dung cho những trang có kích thước khác hoặc các phần mềm trình diễn như Power Point hoặc chuyển sang định dạng HTML. Chế độ này sẽ sử dụng cách phân tích trình bày trang và cột để xây dựng lại thứ tự các văn bản nhưng chỉ phục hồi định dạng đoạn, đồ họa, và dữ liệu văn bản. • Plain Text: Nếu bạn chỉ cần văn bản mà không cần định dạng hay trình bày, bạn hãy sử dụng Plain Text. Plain Text sẽ phục hồi các định dạng kí tự, đoạn hoặc đồ họa nhưng chỉ phục hồi văn bản bằng phân tích cột và trình bày trang. • Exact: Nếu bạn cần một tài liệu Word trông giống hệt như tài liệu PDF? Bạn cần thay đổi nhỏ các tập tin này? Exact sử dụng các TextBox của Word để đảm bảo chắc chắn văn bản và đồ họa vẫn giống y nguyên bản PDF gốc.Chế độ Exact không nên sử dụng nếu bạn cần chỉnh sửa rất nhiều nội dung từ Quadratic Functions Quadratic Functions By: OpenStaxCollege An array of satellite dishes (credit: Matthew Colvin de Valle, Flickr) Curved antennas, such as the ones shown in [link], are commonly used to focus microwaves and radio waves to transmit television and telephone signals, as well as satellite and spacecraft communication The cross-section of the antenna is in the shape of a parabola, which can be described by a quadratic function In this section, we will investigate quadratic functions, which frequently model problems involving area and projectile motion Working with quadratic functions can be less complex than working with higher degree functions, so they provide a good opportunity for a detailed study of function behavior 1/41 Quadratic Functions Recognizing Characteristics of Parabolas The graph of a quadratic function is a U-shaped curve called a parabola One important feature of the graph is that it has an extreme point, called the vertex If the parabola opens up, the vertex represents the lowest point on the graph, or the minimum value of the quadratic function If the parabola opens down, the vertex represents the highest point on the graph, or the maximum value In either case, the vertex is a turning point on the graph The graph is also symmetric with a vertical line drawn through the vertex, called the axis of symmetry These features are illustrated in [link] The y-intercept is the point at which the parabola crosses the y-axis The x-intercepts are the points at which the parabola crosses the x-axis If they exist, the x-intercepts represent the zeros, or roots, of the quadratic function, the values of x at which y = Identifying the Characteristics of a Parabola Determine the vertex, axis of symmetry, zeros, and y-intercept of the parabola shown in [link] 2/41 Quadratic Functions The vertex is the turning point of the graph We can see that the vertex is at (3, 1) Because this parabola opens upward, the axis of symmetry is the vertical line that intersects the parabola at the vertex So the axis of symmetry is x = This parabola does not cross the x-axis, so it has no zeros It crosses the y-axis at (0, 7) so this is the y-intercept Understanding How the Graphs of Parabolas are Related to Their Quadratic Functions The general form of a quadratic function presents the function in the form f(x) = ax2 + bx + c where a, b, and c are real numbers and a ≠ If a > 0, the parabola opens upward If a < 0, the parabola opens downward We can use the general form of a parabola to find the equation for the axis of symmetry 3/41 Quadratic Functions b The axis of symmetry is defined by x = − 2a If we use the quadratic formula, − b ± √b2 − 4ac x= , to solve ax2 + bx + c = for the x-intercepts, or zeros, we find the 2a value of x halfway between them is always x = − symmetry b 2a , the equation for the axis of [link] represents the graph of the quadratic function written in general form as y = x2 + 4x + In this form, a = 1, b = 4, and c = Because a > 0, the parabola opens upward The axis of symmetry is x = − 2(1) = − This also makes sense because we can see from the graph that the vertical line x = − divides the graph in half The vertex always occurs along the axis of symmetry For a parabola that opens upward, the vertex occurs at the lowest point on the graph, in this instance, ( − 2, − 1) The x-intercepts, those points where the parabola crosses the x-axis, occur at ( − 3, 0) and ( − 1, 0) 4/41 Quadratic Functions The standard form of a quadratic function presents the function in the form f(x) = a(x − h)2 + k where (h, k) is the vertex Because the vertex appears in the standard form of the quadratic function, this form is also known as the vertex form of a quadratic function As with the general form, if a > 0, the parabola opens upward and the vertex is a minimum If a < 0, the parabola opens downward, and the vertex is a maximum [link] represents the graph of the quadratic function written in standard form as y = −3(x + 2) + Since x – h = x + in this example, h = –2 In this form, a = −3, h = −2, and k = Because a < 0, the parabola opens downward The vertex is at ( − 2, 4) 5/41 Quadratic Functions The standard form is useful for determining how the graph is transformed from the graph of y = x2 [link] is the graph of this basic function 6/41 Quadratic Functions If k > 0, the graph shifts upward, whereas if k < 0, the graph shifts downward In [link], k > 0, so the graph is shifted units upward If h > 0, the graph shifts toward the right and if h < 0, the graph shifts to the left In [link], h < 0, so the graph is shifted units to the left The magnitude of a indicates the stretch of the graph If|a| > 1, the point associated with a particular x-value shifts farther from the x-axis, so the graph appears to become narrower, and there is a vertical stretch But if |a| < 1, the point associated with a particular x-value shifts closer to the x-axis, so the graph appears to become wider, but in fact there is a vertical ... Single Row Functions 3 Introduction to Oracle: SQL and PL/SQL Using Procedure Builder3Ć2 Single Row Functions 3Ć3 Objectives Functions make the basic query block more powerful and are used to manipulate data values. This is the first of two lessons that explore functions. You will focus on single row character, number, and date functions, as well as those functions that convert data from one type to another, for example, character data to numeric. At the end of this lesson, you should be able to D Explain the various types of functions available in SQL. D Identify the basic concepts of using functions. D Use a variety of character, number, and date functions in SELECT statements. D Explain the conversion functions and how they might be used. Introduction to Oracle: SQL and PL/SQL Using Procedure Builder3Ć4 Single Row Functions 3Ć5 Overview Functions are a very powerful feature of SQL and can be used to D Perform calculations on data. D Modify individual data items. D Manipulate output for groups of rows. D Alter date formats for display. D Convert column datatypes. There are two distinct types of functions: D Single row functions. D Multiple row functions. Single Row Functions These functions operate on single rows only, and return one result per row. There are different types of single row functions. We will cover those listed below. D Character D Number D Date D Conversion Multiple Row Functions These functions manipulate groups of rows to give one result per group of rows. For more information, see Oracle7 Server SQL Reference, Release 7.3 for the complete list of available functions and syntax. Introduction to Oracle: SQL and PL/SQL Using Procedure Builder3Ć6 Single Row Functions 3Ć7 Single Row Functions Single row functions are used to manipulate data items. They accept one or more arguments and return one value for each row returned by the query. An argument may be one of the following: D A user-supplied constant D A variable value D A column name D An expression Features of Single Row Functions D They act on each row returned in the query. D They return one result per row. D They may return a data value of a different type than that referenced. D They may expect one or more user arguments. D You can nest them. D You can use them in SELECT, WHERE, and ORDER BY clauses. Syntax function_name (column|expression, [arg1, arg2, .]) where: function_name is the name of the function. column is any named database column. expression is any character string or calculated expression. arg1, arg2 is any argument to be used by the function. Introduction to Oracle: SQL and PL/SQL Using Procedure Builder3Ć8 Single Row Functions 3Ć9 Character Functions Single row character functions accept character data as input and can return both character and number values. Function Purpose LOWER(column|expression) Converts alpha character values to lowercase. UPPER(column|expression) Converts alpha character values to uppercase. INITCAP(column|expression) Converts alpha character values to uppercase for the first letter of each word, all other letters in lowercase. CONCAT(column1|expression1, column2|expression2) Concatenates the first character value to the second character value. Equivalent to concatenation operator (||). SUBSTR(column|expression,m[,n]) Returns specified characters from character value starting at character position m, n characters long. If m is negative, the count starts from the end of the character value. LENGTH(column|expression) Returns the number of characters in value. NVL(column|expression1,column|ex pression2) Converts the the first value if null to the 5.10 Polynomial Approximation from Chebyshev Coefficients 197 Sample page from NUMERICAL RECIPES IN C: THE ART OF SCIENTIFIC COMPUTING (ISBN 0-521-43108-5) Copyright (C) 1988-1992 by Cambridge University Press.Programs Copyright (C) 1988-1992 by Numerical Recipes Software. Permission is granted for internet users to make one paper copy for their own personal use. Further reproduction, or any copying of machine- readable files (including this one) to any servercomputer, is strictly prohibited. To order Numerical Recipes books,diskettes, or CDROMs visit website http://www.nr.com or call 1-800-872-7423 (North America only),or send email to trade@cup.cam.ac.uk (outside North America). 5.10 Polynomial Approximation from Chebyshev Coefficients You may well ask after reading the preceding two sections, “Must I store and evaluate my Chebyshev approximation as an array of Chebyshev coefficients for a transformed variable y? Can’t I convert the c k ’s into actual polynomial coefficients in the original variable x and have an approximation of the following form?” f(x) ≈ m−1 k=0 g k x k (5.10.1) Yes, you can do this (and we will give you the algorithm to do it), but we caution you against it: Evaluating equation (5.10.1), where the coefficient g’s reflect an underlying Chebyshev approximation, usually requires more significant figures than evaluation of the Chebyshev sum directly (as by chebev). This is because the Chebyshev polynomials themselves exhibit a rather delicate cancellation: The leading coefficient of T n (x), for example, is 2 n−1 ; other coefficients of T n (x) are even bigger; yet they all manage to combine into a polynomial that lies between ±1. Only when m is no larger than 7 or 8 should you contemplate writing a Chebyshev fit as a direct polynomial, and even in those cases you should be willing to tolerate two or so significant figures less accuracy than the roundoff limit of your machine. You get the g’s in equation (5.10.1) from the c’s output from chebft (suitably truncated atamodest value of m)bycallinginsequencethe followingtwoprocedures: #include "nrutil.h" void chebpc(float c[], float d[], int n) Chebyshev polynomial coefficients. Given a coefficient array c[0 n-1] , this routine generates a coefficient array d[0 n-1] such that n-1 k=0 d k y k = n-1 k=0 c k T k (y) − c 0 /2.Themethod is Clenshaw’s recurrence (5.8.11), but now applied algebraically rather than arithmetically. { int k,j; float sv,*dd; dd=vector(0,n-1); for (j=0;j<n;j++) d[j]=dd[j]=0.0; d[0]=c[n-1]; for (j=n-2;j>=1;j--) { for (k=n-j;k>=1;k--) { sv=d[k]; d[k]=2.0*d[k-1]-dd[k]; dd[k]=sv; } sv=d[0]; d[0] = -dd[0]+c[j]; dd[0]=sv; } for (j=n-1;j>=1;j--) d[j]=d[j-1]-dd[j]; d[0] = -dd[0]+0.5*c[0]; free_vector(dd,0,n-1); } 198 Chapter 5. Evaluation of Functions Sample page from NUMERICAL RECIPES IN C: THE ART OF SCIENTIFIC COMPUTING (ISBN 0-521-43108-5) Copyright (C) 1988-1992 by Cambridge University Press.Programs Copyright (C) 1988-1992 by Numerical Recipes Software. Permission is granted for internet users to make one paper copy for their own personal use. Further reproduction, or any copying of machine- readable files (including this one) to any servercomputer, is strictly prohibited. To order Numerical Recipes books,diskettes, or CDROMs visit website http://www.nr.com or call 1-800-872-7423 (North America only),or send email to trade@cup.cam.ac.uk (outside North America). void pcshft(float a, float b, float d[], int n) Polynomial coefficient shift. Given a coefficient array d[0 n-1] , this routine generates a coefficient array g [0 n-1] such that n-1 k=0 d k y k = n-1 k=0 g k x k ,wherexand y are related by (5.8.10), i.e., the interval −1 <y<1is mapped to the interval a <x< b . The array g is returned in d . { int k,j; float fac,cnst; cnst=2.0/(b-a); fac=cnst; for (j=1;j<n;j++) { First we rescale by the factor const . 2003 Prentice Hall, Inc. All rights reserved. 1 Chapter 3 - Functions Outline 3.1 Introduction 3.2 Program Components in C++ 3.3 Math Library Functions 3.4 Functions 3.5 Function Definitions 3.6 Function Prototypes 3.7 Header Files 3.8 Random Number Generation 3.9 Example: A Game of Chance and Introducing enum 3.10 Storage Classes 3.11 Scope Rules 3.12 Recursion 3.13 Example Using Recursion: The Fibonacci Series 3.14 Recursion vs. Iteration 3.15 Functions with Empty Parameter Lists 2003 Prentice Hall, Inc. All rights reserved. 2 Chapter 3 - Functions Outline 3.16 Inline Functions 3.17 References and Reference Parameters 3.18 Default Arguments 3.19 Unary Scope Resolution Operator 3.20 Function Overloading 3.21 Function Templates 2003 Prentice Hall, Inc. All rights reserved. 3 3.1 Introduction • Divide and conquer – Construct a program from smaller pieces or components – Each piece more manageable than the original program 2003 Prentice Hall, Inc. All rights reserved. 4 3.2 Program Components in C++ • Modules: functions and classes • Programs use new and “prepackaged” modules – New: programmer-defined functions, classes – Prepackaged: from the standard library • Functions invoked by function call – Function name and information (arguments) it needs • Function definitions – Only written once – Hidden from other functions 2003 Prentice Hall, Inc. All rights reserved. 5 3.3 Math Library Functions • Perform common mathematical calculations – Include the header file <cmath> • Functions called by writing – functionName(argument1, argument2, …); •Example cout << sqrt( 900.0 ); – sqrt (square root) function The preceding statement would print 30 – All functions in math library return a double 2003 Prentice Hall, Inc. All rights reserved. 6 3.3 Math Library Functions • Function arguments can be – Constants • sqrt( 4 ); –Variables • sqrt( x ); – Expressions • sqrt( sqrt( x ) ) ; • sqrt( 3 - 6x ); 2003 Prentice Hall, Inc. All rights reserved. 7 Method Description Example ceil( x ) rounds x to the sm allest integer not less than x ceil( 9.2 ) is 10.0 ceil( -9.8 ) is -9.0 cos( x ) trigonometric cosine of x (x in radians) cos( 0.0 ) is 1.0 exp( x ) exponential function ex exp( 1.0 ) is 2.71828 exp( 2.0 ) is 7.38906 fabs( x ) absolute value of x fabs( 5.1 ) is 5.1 fabs( 0.0 ) is 0.0 fabs( -8.76 ) is 8.76 floor( x ) rounds x to the largest integer not greater than x floor( 9.2 ) is 9.0 floor( -9.8 ) is -10.0 fmod( x, y ) rem ainder of x/y as a floating- point number fmod( 13.657, 2.333 ) is 1.992 log( x ) natural logarithm of x (base e) log( 2.718282 ) is 1.0 log( 7.389056 ) is 2.0 log10( x ) logarithm of x (base 10) log10( 10.0 ) is 1.0 log10( 100.0 ) is 2.0 pow( x, y ) x raised to pow er y (xy) pow( 2 , 7 ) is 128 pow( 9 , .5 ) is 3 sin( x ) trigonometric sine of x (x in radians) sin( 0.0 ) is 0 sqrt( x ) square root of x sqrt( 900.0 ) is 30.0 sqrt( 9.0 ) is 3.0 tan( x ) trigonometric tangent of x (x in radians) tan( 0.0 ) is 0 Fig . 3.2 M a th lib ra ry func tio ns. 2003 Prentice Hall, Inc. All rights reserved. 8 3.4 Functions • Functions – Modularize a program – Software reusability • Call function multiple times • Local variables – Known only in the function in which they are defined – All variables declared in function definitions are local variables • Parameters – Local variables passed to function when called – Provide outside information 2003 Prentice Hall, Inc. All rights reserved. 9 3.5 Function Definitions • Function prototype – Tells compiler argument type and return type of function – int square( int ); • Function takes an int and returns an int – Explained in more detail later • Calling/invoking a function – square(x); – After finished, passes back result 2003 Prentice Hall, Inc. All rights Outsourcing Management Functions for the Acquisition of Federal Facilities (Free Executive Summary) http://www.nap.edu/catalog/10012.html Free Executive Summary ISBN: 978-0-309-07267-0, 152 pages, 6 x 9, paperback (2000) This executive summary plus thousands more available at www.nap.edu. Outsourcing Management Functions for the Acquisition of Federal Facilities Committee on Outsourcing Design and Construction-Related Management Services for Federal Facilities, Board on Infrastructure and the Constructed Environment, National Research Council This free executive summary is provided by the National Academies as part of our mission to educate the world on issues of science, engineering, and health. If you are interested in reading the full book, please visit us online at http://www.nap.edu/catalog/10012.html . You may browse and search the full, authoritative version for free; you may also purchase a print or electronic version of the book. If you have questions or just want more information about the books published by the National Academies Press, please contact our customer service department toll-free at 888-624-8373. COMMITTEE ON OUTSOURCING DESIGN CONTRUCTION- RELATED MANAGEMENT SERVICES FOR FEDERAL FACILITIESHENRY L. MICHEL, Chair, Parson Brinckerhoff, New York, New YorkJOSEPH A. AHEARN, CH2M Hill, Greenwood Village, ColoradoA. WAYNE COLLINS, Arizona Department of Transportation, PhoenixJOHN D. DONAHUE, Harvard University, Cambridge, MassachusettsLLOYD A. DUSCHA, Consulting Engineer, Reston, VirginiaG. BRIAN ESTES, Consulting Engineer, Williamsburg, VirginiaMARK C. FRIEDLANDER, Schiff, Harden, and Waite, Chicago, IllinoisHENRY J. HATCH, American Society of Civil Engineers, Reston, VirginiaSTEPHEN C. MITCHELL, Lester B. Knight and Associates, Inc., Chicago, IllinoisKARLA SCHIKORE, Consultant, Petaluma, CaliforniaE. SARAH SLAUGHTER, MOCA, Inc., Newton, MassachusettsLUIS M. TORMENTA, The LIRO Group, New York, New YorkRICHARD L. TUCKER, University of Texas at AustinNORBERT W. YOUNG, JR., McGraw-Hill Companies, New York, New YorkStaffRICHARD G. LITTLE, Director, Board on Infrastructure and the Constructed EnvironmentLYNDA L. STANLEY, Study DirectorJOHN A. WALEWSKI, Project OfficerLORI J. VASQUEZ, Administrative AssociateNICOLE E. LONGSHORE, Project Assistant Copyright © National Academy of Sciences. All rights reserved. Unless otherwise indicated, all materials in this PDF file are copyrighted by the National Academy of Sciences. Distribution or copying is strictly prohibited without permission of the National Academies Press http://www.nap.edu/permissions/ Permission is granted for this material to be posted on a secure password-protected Web site. The content may not be posted on a public Web site. Copyright © National Academy of Sciences. All rights reserved. This executive summary plus thousands more available at http://www.nap.edu Outsourcing Management Functions for the Acquisition of Federal Facilities http://books.nap.edu/catalog/10012.html 1 Executive Summary In this study outsourcing is defined as the organizational practice of con- tracting for services from an external entity while retaining control over assets and oversight of the services being outsourced. In the 1980s, a number of factors led to a renewed interest in outsourcing. For private sector organizations, outsourcing was identified as a strategic component of business process reengineering—an effort to ... practice with quadratic equations • • • • Graphing Quadratic Functions in General Form Graphing Quadratic Functions in Standard Form Quadratic Function Review Characteristics of a Quadratic Function... the quadratic function We can see where the maximum area occurs on a graph of the quadratic function in [link] How To 17/41 Quadratic Functions Given an application involving revenue, use a quadratic. .. solved by graphing the quadratic as in [link] We can see the maximum revenue on a graph of the quadratic function 19/41 Quadratic Functions Finding the x- and y-Intercepts of a Quadratic Function