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Edumatter-814: School Math Calculators and Equation Solvers

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17 Feb 2015CPOL14 min read 72K   33   20
Educational software package for Microsoft Windows® 7/8 contains “5-in-1” School Math Calculators and Equation Solvers intended for students and educators

Project status

This project (originally named "Edumatter® M-12") was a winning submission to The Windows 8* & Ultrabook™ App Innovation Contest (AIC-2012).

Educational software package "Edumatter® M-12" (or simply - Edumatter) for Microsoft Windows® developed by Dr. Alexander Bell (Infosoft International Inc, NY) is intended for public/private school (K-12) and college students, educators, and self-paced education/home schooling.

The application software package ("bundle") contains 2 core applications and one optional app extension:

  • Math Calculator and Equation Solver Edumatter M12-L "Light" edition (core app [1], AppUp® download)
  • Math Calculator and Equation Solver Edumatter M-12 "Standard" edition (core app [2], AppUp® download)

Core applications (i.e. Edumatter M-12/M12-L) can run on any HW platform equipped with Microsoft Windows OS 7/8 (any edition) in either regular desktop "mouse/keyboard" and/or touch-screen modes. User can download either free "Light" edition or reasonably priced "Standard" edition: the latter included basic tutors' search options.

The application extension ('FindTutor") can operate as a standalone desktop app, extending the functionality of the core applications. It s optimized for novel product line of Ultrabooks™ inspired by Intel Corporation and requires Windows 8 (any edition) and GPS/Gelocation features to be enabled on the client computer in order to provide sophisticates tutors' search option applied to interactive online Microsoft Bing map (technology partially described in the article on Codeproject [8]).

Important note: core applications (Edumatter M-12/M12-L) are well-suited for a wide target auditorium and various age groups. Application extension "FindTutor", which among other features implements real-time GPS/geo-location info retrieval, is intended for a more senior auditorium due to Privacy Protection concerns. Please refer to the "User Manual" and "End User License Agreement" for more details on this rather important issue.

Category 1: Education

Category 2: Productivity

Platform: Desktop app for Win 7/8, any edition

All applications included in the aforementioned software package ("bundle") are available on Intel's AppUp store [1...3]. Sample screenshots are included in this article, and also available as a slide-show in [4].

Ultrabook features to utilize in application

  • Touch-screen and keyboard/mouse operation mode
  • Geolocation/GPS Sensor to search target/local areas for Math Tutors, SAT, ACT, GED prep, etc.
  • Multi-core CPU (i3/i5/i7) to implement efficient parallel algorithms, in particular, prime factoring
  • Multi-modal speech-enhanced UI, utilizing high-responsiveness of Ultrabooks and providing Voice messaging to Users via TTS (Text-to-Speech) technology.
Other sales points:
  • Unique ability to operate on any combination of fractions, mixed numbers, decimals and integers; results are also displayed as both fractions and decimals.
  • Fast Prime-factoring algorithm capable of cracking down up to 18-digit integers.
  • Computational efficiency benchmarks on general Math operations, prime factoring and parallel processing algorithms, particular important on HW platform powered by Intel's multi-core CPU

Background

Core application (Edumatter M-12/M12-L) is configured as modular “5-in-1” School Math Calculators and Equation Solvers software package containing 5 modules listed below:

  • FC12 Fraction Calculator
  • PF12 Prime Factoring Calculator
  • LE12 Linear Equation Solver
  • SE12 System of Linear Equation Solver
  • QE12 Quadratic Equation Solver

Image 1

Fig. 1: Edumatter M12 core app, sample screenshot

Each module provides unique capability of processing any combination of fractions (proper/improper), whole or mixed numbers, and decimals. Calculation results are also shown in both fractional and decimal forms except for quadratic equation solver (QE12), which outputs either real or complex numbers in decimal form only (for the obvious reason that the roots of the latter can be irrational numbers).

Fraction Calculator FC12

Fraction Calculator FC12 extends the functionality of the popular online Multiple Fractions Calculator [7] (note: its online counterpart is topping Google search list for many years). Dedicated slideshow is available online at [4]. Coding solutions were partially discussed in Codeproject articles [5,6].

FC-12 can perform binary and unary arithmetic operations on any combinations of whole and mixed number, fractions (proper/improper), and decimal numbers (positive/negative), like: 4, 8.75, 2/3, 9/4, 3 5/7, -6 2/3, 9, 8.75, -12. Any fraction or mixed number can be reduced to the lowest terms. Any improper fraction could be converted to mixed number and vice versa. As an additional convenience feature, all calculation results appear in “History” text box, so they can be copied to computer “Clip Board” memory, or stored in the standard text file for future use.

Image 2

Fig. 2: Fraction Calculator FC-12, sample screenshot

Prime Factoring Calculator PF12

As a reminder, prime factoring refers to finding non-trivial factors of any positive integer (whole) number, where trivial factors of any whole number are just the number 1 and the number itself. Any other factors are considered non-trivial, for example, number 6 has two non-trivial factors: 6 = 2*3.

Prime Factoring Calculator PF12 implements effective computational algorithm that can perform fast prime factoring of any integer number up to 18 digits (!), essentially unparalleled in any commercially available school math calculators. Results are displayed in calculation history text box and also can be copied to computer “Clip Board” memory, or stored in the standard text file for future use.

Image 3

Fig. 3: Prime Factoring Calculator PF-12, sample screenshot

Linear Equation Solver LE12

As a reminder, Linear Equation in its canonical form can be written as:
AX + B = C,
where numbers A, B and C are called the coefficients of the equation. The general solution to the Linear equation is: X = (C-B)/A

Linear Equation Solver LE12 is capable of solving linear equation with fractional or whole coefficients. Results are displayed as both fractions and equivalent decimals in calculation history text box, and also can be copied to computer “Clip Board” memory, or stored in the standard text file for future use.

System of Linear Equation Solver SE12

As a reminder, system of linear equations in its canonical form can be written as:
A1X + B1Y= C1
A2X + B2Y= C2

System of Linear Equation Solver SE12 is capable of solving system of linear equations with fractional, decimal or integer coefficients (see sample screenshot #4 included in slide show [1]). Results are displayed as fractions and equivalent decimals in calculation history text box, and also can be copied to computer “Clip Board” memory, or stored in the standard text file for future use.

Image 4

Fig. 4: System of Linear Equations Solver SE-12, sample screenshot

Quadratic Equation Solver QE12

As a reminder, quadratic equations in its canonical form can be written as: Ax^2+Bx+C=0.

Quadratic Equation Solver QE12 is capable of solving quadratic equations with fractional or whole coefficients. Its output can be either real or complex numbers presented in decimal form only: as we shall know from the theory (see recommended links attached to the article), the solution to quadratic equation might be irrational numbers, thus it could not be presented by any finite fraction. As in all previous cases, calculation results appear in history box and can be copied to computer “Clip Board”, or stored in the standard text file.

Image 5

Fig. 5: Quadratic Equation Solver QE-12, sample screenshot

Using the code

Core algorithms implemented in Fraction Calculator FC12 were previously published and discussed in the Tip section on Codeproject [5,6]. Fraction arithmetic utilizes novel computation engine, extending existing numeric types with two interrelated classes, namely: Fraction and Mixed Number. The latter is a most universal type combining integer and fractional parts. Following code snippet (Listing 1.) demonstrates implementation details of Fraction class, including its comprehensive error handling, operators overloading and methods overriding techniques:

Listing 1. Implementation details of Fraction class
C#
#region private Vars
private Int64 _n; // var containing Numerator
private Int64 _d; // var containing Denominator (positive num)
#endregion

#region private vars: error msg
private const string errMsgDivBy0 = "Division by 0";
private const string errMsgDenom = "Denominator must be >0";
private const string errMsgNotFraction = "Not a valid Fraction";
private const string errMsgOutOfRange = "Number out of range";
private const string errMsgStackOverflow = "Stack Overflow";
private const string errMsgArithmetic = "Arithmetic error";
#endregion

#region public properties: Numerator and Denominator
/// <summary>Numerator: Int64</summary>
internal Int64 Numerator
{
    get { return _n; }
    set {_n = checked(value);}
}

/// <summary>Numerator: Int64 (>0)</summary>
internal Int64 Denominator
{
    get { return _d; }
    set
    {
        if (value <= 0) { throw (new ArgumentException(errMsgDenom)); }
        else{ _d = checked(value); }
    }
}
#endregion

#region public ctor:  Fraction(Int64 N, Int64 D)
/// <summary>ctor: parameterless</summary>
internal Fraction() { }

/// <summary>ctor w/parameters</summary>
/// <param name="N">Int64</param>
/// <param name="D">Int64; must be >0</param>
internal Fraction(Int64 N, Int64 D)
{
    _n = checked(N);
    if (D <= 0) { throw (new ArgumentException(errMsgDenom)); }
    else { _d = checked(D); }
}
#endregion

#region Fraction.ToString() override method
/// <summary>
/// Fraction.ToString() override method
/// </summary>
/// <returns></returns>
public override string ToString()
{
    try
    {
        if (_n == 0) return "0";
        if (_d == 1) return _n.ToString();
        return (_n.ToString() + "/" + _d.ToString());
    }
    catch (ArgumentOutOfRangeException) { throw new ArgumentOutOfRangeException(errMsgOutOfRange); }
    catch (DivideByZeroException) { throw new DivideByZeroException(errMsgDivBy0); }
    catch (StackOverflowException) { throw new StackOverflowException(errMsgStackOverflow); }
    catch (ArithmeticException) { throw new ArithmeticException(errMsgArithmetic); }
    catch (ArgumentException) { throw new ArgumentException(errMsgNotFraction); }
    catch { throw; }
}
#endregion

#region Fractions Arithmetic: Operators overload
/// <summary>
/// Add 2 Fractions, use LCM
/// </summary>
/// <param name="Fraction1">Fraction</param>
/// <param name="Fraction2">Fraction</param>
/// <returns>Fraction</returns>
public static Fraction operator +(Fraction Fraction1, Fraction Fraction2)
{
    Fraction ret = new Fraction();
    Int64 _lcm;

    // validate denominator for 0
    if (Fraction1.Denominator == 0 || Fraction2.Denominator == 0)
    { throw (new DivideByZeroException(errMsgDivBy0)); }

    // validate denominator for negatives
    if (Fraction1.Denominator < 0 || Fraction2.Denominator < 0)
    { throw (new ArgumentException(errMsgDenom)); }

    try
    {
        // find LCM of two denominators
        _lcm = checked (Integers.LCM(Fraction1.Denominator, Fraction2.Denominator));

        // calculate numerator using LCM values
        ret.Numerator =
            checked((Int64)(checked (Fraction1.Numerator * (Int64)(_lcm/Fraction1.Denominator)) +
            checked (Fraction2.Numerator * (Int64)(_lcm/Fraction2.Denominator))));

        // set resulting denominator to LCM
        ret.Denominator = _lcm;

        // return fraction
        return ret;
    }
    catch (ArgumentOutOfRangeException) { throw new ArgumentOutOfRangeException(errMsgOutOfRange); }
    catch (DivideByZeroException) { throw new DivideByZeroException(errMsgDivBy0); }
    catch (StackOverflowException) { throw new StackOverflowException(errMsgStackOverflow); }
    catch (ArithmeticException) { throw new ArithmeticException(errMsgArithmetic); }
    catch (ArgumentException) { throw new ArgumentException(errMsgNotFraction); }
    catch { throw; }
    finally { ret = null; }
}
#endregion

 

Prime Factoring PF-12 module implements novel parallel algorithm, efficiently utilizing the power of Ultrabooks multi-core CPU (like i3/i5/i7) to speed up prime factors calculations. Following code snippet (Listing 2) demonstrates the parallel implementation of "find first non-trivial factor" algorithm, which provides significant performance improvement vs. serial implementation in case of factoring big primes:

Listing 2. Fast parallel algorithm to find first non-trivial factor of integer number (Int64)
C#
#region GetFirstFactorParallel(Int64 Num) algorithm
/// <summary>
/// ===================================================================
/// Copyright(C)2012 Alexander Bell
/// ===================================================================
/// parallel algorithm accepts Int64 Num 
/// and returns either first found not-trivial factor, or number 1.
/// Note: not-trivial factor can be relatively small composite number,
/// thus it requires subsequent factoring of itself, adding very 
/// small overhead, because its value is far less than SQRT(Num)
/// This algo provides significant performance boost 
/// in comparison to serial implementation while prime factoring
/// big prime numbers, like for e.g. 18-digit primes:
/// 999999999999999989
/// 999999999999999967
/// 999999999999999877
/// 999999999999999863
/// 999999999999999829
/// or 17-digit primes:
/// 99999999999999997
/// 99999999999999977
/// 99999999999999961
/// 99999999999999943
/// 99999999999999919
/// </summary>
/// <param name="Num">Int64</param>
/// <returns>Int64</returns>
internal static Int64 GetFirstFactorParallel(Int64 Num)
{
    // use concurrent stack to store non-trivial factor if found
    ConcurrentStack<Int64> _stack = new ConcurrentStack<Int64>();
            
    // object to specify degrees of parallelism
    ParallelOptions _po = new ParallelOptions();

    try
    {
        // return value initially set to 1
        Int64 _ret = 1;

        // step 1: try to factor on base 2, return if OK
        if (Num % 2 == 0) return 2;

        // step 2: try to factor on base 3, return if OK
        if (Num % 3 == 0) return 3;

        #region parallel algo to find first non-trivial factor if exists

        // set upper limit
        Int64 _upMargin = (Int64)Math.Sqrt(Num) + 1;

        // number of CPU cores
        int _countCPU = System.Environment.ProcessorCount;

        // max degree of parallelism set equal to _cpuCount
        _po.MaxDegreeOfParallelism = _countCPU;

        Parallel.For(0, 2, _po, (i, _plState) =>
        {
            // starting number for inner loops (5 and 7)
            int _seed = 5 + 2 * i;

            // inner loops running in parallel;
            // notice that because input Num was already tested for factors 2 and 3,
            // then increment of 6 is used to speed up the processing,
            // thus in dual core CPU it looks like:
            // 5, 11, 17, 23, 29, etc. in first thread
            // 7, 13, 19, 25, 31, etc, in second thread
            for (Int64 j = _seed; j < _upMargin; j += 6)
            {
                // exit loop if stack contains value
                if (_stack.Count != 0) { break; }

                // check divisibility
                if (Num % j == 0)
                {
                    // push non-trivial factor to ConcurrentStack and exit loop
                    if (_stack.Count == 0) { _stack.Push(j); }
                    break;
                }
            }
        });
        #endregion

        // return the value in ConcurrentStack if exists, or 1
        return (_stack.TryPop(out _ret)) ? _ret : 1;
    }
    catch { throw; }
    finally { _po = null; _stack = null; }

}
#endregion

Important: this parallel algo requires library references:

C#
using System.Collections.Concurrent;
using System.Threading.Tasks;

For smaller integers (less than 10-digits), serial implementation may provide better performance than parallel algorithm described above due to thread synchronization and control logic overhead in the latter one. Following code snippet (Listing 3) demonstrates serial implementation of the efficient prime factoring algorithm:

Listing 3. Fast Prime Factoring Algorithm of integer numbers (Int64), serial implementation
C#
#region PrimeFactoringSerial(Int64 Num) algorithm
/// <summary>
/// =======================================================
/// Copyright(C)2012 Alexander Bell
/// =======================================================
/// get list of prime factors of Int64 Num in serial mode
/// </summary>
/// <param name="Num">Int64</param>
/// <returns>List<Int64></returns>
internal static List<Int64> PrimeFactoringSerial(Int64 Num)
{
    // list of Prime Factors to return
    List<Int64> _lstFactors = new List<Int64>();

    // temp var to store intermediate result (_num/factors)
    Int64 _num = Num; 

    #region factorize on base 2
    // divide by mod 2, add to the list if successful,
    // try again on new number (_num / 2)
    while (_num % 2 == 0)
    {
        _lstFactors.Add(2);
        _num = (Int64)(_num / 2);
    }

    // if _num==1 then stop factoring and return
    if (_num == 1) { return _lstFactors; }
    #endregion

    #region try factoring in range: 3 ... Math.Sqrt(_num) + 1;
    // set initial upper limit
    Int64 _upMargin = (Int64)Math.Sqrt(_num) + 1;

    // loop with variable upper limit;
    // notice increment of 2 to loop through odd numbers only
    for (Int64 i=3; i<=_upMargin; i+=2)
    {
        if (_num % i == 0)
        {
            // add prime factor to the List
            _lstFactors.Add(i);

            // get new integer to factorize (_num)
            _num = (Int64) (_num / i);

            // calculate the loop upper limit corresponding to new _num
            _upMargin = (Int64) Math.Sqrt(_num) + 1;

            // keep value of (i) the same in next iteration
            i-=2;
        }
    }

    // add the last factor
    _lstFactors.Add(_num);

    // sort list
    _lstFactors.Sort();

    return _lstFactors;
    #endregion
}
#endregion  

FindTutor-2013 application extension implements solution utilizing Microsoft Bing map technology, partially described in Codeproject article [8].

Geolocation/GPS features and Custom map search

FindTutor-2013 application utilizes novel Geolocation/GPS features of Ultrabooks that allows retrieval of geographic coordinates (Latitude, Longitude and optional accuracy) in real-time mode. These coordinates are used to identify a center of POI (points of interest) search area (application also allows manual entry of said coordinates). In order to obtain a set of POI to show up as standard/custom pushpins on the map in the search area, the coordinates of its central point are encoded in web query request to be sent to its online web counterpat, powered by Microsoft Bing mapping technology [8,9].

Microsoft Bing maps implement its own standard "Find What" feature, that allows finding POI in a search area specified by its central point [9]. This standardized Bing Map search is extended with custom search engine based on proprietary database of POI and great-circle (orthodromic) distance computation module [10,11]. Corresponding POI are shown on the map as added custom pushpins of different style and sizes.

Core methods of said engine perform computation of the great-circle distance on Earth between 2 geographical points specified by their Latitude and Longitude: Lat1, Lon1 and Lat2 , Lon2, correspondingly. There are plenty of computational methods described in various online resources (e.g. [12, 13]. One of the popular methods is based on so-called Haversine formula. Following code snippet (Listing 4.) demonstrates speed-optimized C# implementation of this formula:

Listing 4. Haversine formula to calculate great-circle distance between two points on Earth
C#
#region private: const
private const double _radiusEarthMiles = 3959;
private const double _radiusEarthKM = 6371;
private const double _m2km = 1.60934;
private const double _toRad = Math.PI / 180;
#endregion

/// <summary>
/// Haversine formula to calculate
/// great-circle (orthodromic) distance on Earth
/// High Accuracy, Medium speed
/// </summary>
/// <param name="Lat1">double: 1st point Latitude</param>
/// <param name="Lon1">double: 1st point Longitude</param>
/// <param name="Lat2">double: 2nd point Latitude</param>
/// <param name="Lon2">double: 2nd point Longitude</param>
/// <returns>double: distance in miles</returns>
public static double DistanceMilesHaversine(double Lat1,
                                            double Lon1,
                                            double Lat2,
                                            double Lon2)
{
    try
    {
        double _radLat1 = Lat1 * _toRad;
        double _radLat2 = Lat2 * _toRad;
        double _dLatHalf = (_radLat2 - _radLat1) / 2;
        double _dLonHalf = Math.PI * (Lon2 - Lon1) / 360;

        // intermediate result
        double _a = Math.Sin(_dLatHalf);
        _a *= _a;

        // intermediate result
        double _b = Math.Sin(_dLonHalf);
        _b *= _b * Math.Cos(_radLat1) * Math.Cos(_radLat2);

        // central angle, aka arc segment angular distance
        double _centralAngle = 2 * Math.Atan2(Math.Sqrt(_a + _b), Math.Sqrt(1 - _a - _b));

        // great-circle (orthodromic) distance on Earth between 2 points
        return _radiusEarthMiles * _centralAngle;
    }
    catch { throw; }
}

Notice that the computation of the great-circle distance essentially requires finding a central angle (_centralAngle); multiplying it by the radius of the Earth (_radiusEarthMiles = 3959, or _radiusEarthKM = 6371) will result in said distance.

Another well-known formula that utilizes Spherical law of cosines as described in [14] results in a slightly simplified coding technique: just a single line of code needed for the calculation of central angle (_centralAngle). Following code snippet (Listing 5) provides speed-optimized C# implementation of this formula:

Listing 5. Spherical law of cosines formula to calculate great-circle distance between two points on Earth
C#
/// <summary>
/// Spherical Law of Cosines formula to calculate
/// great-circle (orthodromic) distance on Earth;
/// High Accuracy, Medium speed
/// http://en.wikipedia.org/wiki/Spherical_law_of_cosines
/// </summary>
/// <param name="Lat1">double: 1st point Latitude</param>
/// <param name="Lon1">double: 1st point Longitude</param>
/// <param name="Lat2">double: 2nd point Latitude</param>
/// <param name="Lon2">double: 2nd point Longitude</param>
/// <returns>double: distance in miles</returns>
public static double DistanceMilesSLC(  double Lat1,
                                        double Lon1,
                                        double Lat2,
                                        double Lon2)
{
    try
    {
        double _radLat1 = Lat1 * _toRad;
        double _radLat2 = Lat2 * _toRad;
        double _radLon1 = Lon1 * _toRad;
        double _radLon2 = Lon2 * _toRad;

        // central angle, aka arc segment angular distance
        double _centralAngle = Math.Acos(Math.Sin(_radLat1) * Math.Sin(_radLat2) +
                Math.Cos(_radLat1) * Math.Cos(_radLat2) * Math.Cos(_radLon2 - _radLon1));

        // great-circle (orthodromic) distance on Earth between 2 points
        return _radiusEarthMiles * _centralAngle;
    }
    catch { throw; }
}

For relatively small search areas (with radius <200 miles), good accuracy and high speed of computation due to minimal use of triginometric functions, can be achieved by using Spherical Earth projection to a plane formula that applies Pythagorean Theorem as described in [11]. Following code snippet (Listing 5) demostrates speed-optimized C# implementation of this algorithm, that was selected for use in the custom geographical search engine (part of FindTutor-2013 app):

Listing 5. Great-circle distance calculation using Spherical Earth projection formula
C#
/// <summary>
/// Spherical Earth projection to a plane formula (using Pythagorean Theorem)
/// to calculate great-circle (orthodromic) distance on Earth.
/// http://en.wikipedia.org/wiki/Geographical_distance
/// central angle =
/// Sqrt((_radLat2 - _radLat1)^2 + (Cos((_radLat1 + _radLat2)/2) * (Lon2 - Lon1))^2)
/// Medium Accuracy, Fast,
/// relative error less than 0.1% in search area smaller than 250 miles
/// </summary>
/// <param name="Lat1">double: 1st point Latitude</param>
/// <param name="Lon1">double: 1st point Longitude</param>
/// <param name="Lat2">double: 2nd point Latitude</param>
/// <param name="Lon2">double: 2nd point Longitude</param>
/// <returns>double: distance in miles</returns>
public static double DistanceMilesSEP(double Lat1,
                                      double Lon1,
                                      double Lat2,
                                      double Lon2)
{
    try
    {
        double _radLat1 = Lat1 * _toRad;
        double _radLat2 = Lat2 * _toRad;
        double _dLat = (_radLat2 - _radLat1);
        double _dLon = (Lon2 - Lon1) * _toRad;

        double _a = (_dLon) * Math.Cos((_radLat1 + _radLat2) / 2);

        // central angle, aka arc segment angular distance
        double _centralAngle = Math.Sqrt(_a * _a + _dLat * _dLat);

        // great-circle (orthodromic) distance on Earth between 2 points
        return _radiusEarthMiles * _centralAngle;
    }
    catch { throw; }
}
Speech enhancement (TTS)

User Interface (UI) implements optional speech-enhancement features, providing Voice instructions to Users via TTS (Text-to-Speech) technology; this option can be turned On/Off.

Benchmarks

Core applications Edumatter M-12/M12-L include 3 proprietary performance benchmarks, providing the number-crunching efficiency estimates of the client computer, namely:

  • General Math
  • Prime Factoring
  • Parallel Processing algorithm efficiency on Intel i3, i5 or i7 multi-core CPU architecture

Points of Interest

Product availability and compatibility

Core applications "Edumatter M-12/M12-L" are fully compatible with Microsoft Windows 7 or 8, and is optimized to run on Ultrabooks™ (inspired by Intel) hardware platform. It’s backward compatible with previous versions of Windows Vista/XP.

Speech Technology

Edumatter M-12/M12-L core applications and application extension FindTutor implement multi-modal Voice-enhanced User Interface, utilizing Microsoft Speech object library, in particular, TTS (Text-to-Speech) technology set, providing Voice instructions and error messaging to the User. As per actual testing, it was found that TTS greatly benefits from Ultrabooks high internal data rate (due to sophisticated duo SSD/SATA), noticeably reducing the Voice response latency and increasing overall UI responsiveness.

Digitally Signing Microsoft Visual Studio 2010 executable (.exe) and setup (.msi) files

Adding digital signature to Visual Studio output files with Digital Certificate obtained from Certificate Authorities (CA) was found not just a trivial task. The issue is not pertinent just to particular CA (in this case, Comodo [15]), but is rather common to Visual Studio projects (version 2010 was used for Setup projects, that generate installable .msi files). The standard and most intuitive "way of least resistance" of going to Project->Properties -> Signing tab and just entering a strong name key file (which can be, for example, CertificateFile.pfx received from CA) failed with error message like "Cannot import the following key file: CertificateFile.pfx. The key file may be password protected. To correct this, try to import the certificate again or manually install the certificate to the Strong Name CSP with the following key container name...". Obviously, the file CertificateFile.pfx is and must be protected. So, after hours of Google and numerous "try-error" attempts it became clear that one of the most reliable and straightforward ways to sign VS project outputs (.exe and/or .msi) is to use command line [16] added to post build events that utilizes signtool.exe (latter is included in Microsoft SDK [17], that can be downloaded for free) like shown in the following examples:

Digitally Signing .exe files in VS 2010 using signtool.exe and command line

In Visual Studio 2010 Project (the same technique can apply to VS 2012), open Properties->Build Events tab. In "Post-build event command line" text-box, add the command, which should look like the following (notice that command is pointing to "obj" dir, not "bin"):

"%ProgramFiles%\Microsoft SDKs\Windows\v7.0A\Bin\signtool.exe" sign /n [Company Name] /f C:\CA\CertificateFile.pfx /p password /t http://timestamp.comodoca.com/authenticode "$(ProjectDir)obj/x86/Release/YourProduct.exe"
Digitally Signing .msi files in VS 2010 using signtool.exe and command prompt

In Visual Studio 2010 Setup Project, find the item "PostBuildEvent" in Solution Explorer, and enter command line similar to the one shown below:

"%ProgramFiles%\Microsoft SDKs\Windows\v7.0A\Bin\signtool.exe" sign /n "Infosoft Intl Inc" /f C:\CA\CertificateFile.pfx /p password /t http://timestamp.comodoca.com/authenticode "$(ProjectDir)Release/Setup.msi"

Note, that [Company Name] like "Infosoft Intl Inc" shown in the sample above is just an optional parameter and can be omitted. TimeStamp server in these examples corresponds to aforementioned CA Comodo [15]; certificate file name/location (C:\CA\CerticateFile.pfx) are shown for demo purpose only.

ALS Sensor use-case

Core applications Edumatter M-12/M12-L are potentially capable of automated style selection, for example switching between High/Low contrast color scheme based upon data feed from the ambient light sensor (ALS), included in some high-end Ultrabooks. The possible implementation will require some sort of programmatic equivalent of "comparator w/hysteresis" (well- known in Electrical Engineering) observing ALS data stream and automatically switching between styles based upon some predefined luminance threshold(s). Upon serious design consideration and partial prototype testing, such automatic control feature was found unnecessary in this type of applications: "irrational exuberance", i.e. artificial overstretching of sensors use-cases can potentially result in continuous "styles jitter", thus increasing the annoyance/eye-irritation and degrading the overall user experience rather than improving it. Alternatively, the style selection feature was implemented as a simple menu option (refer to the manual for details).

Real-life design considerations

As mentioned above, core applications (Edumatter M12/M12-L) are well suited for a wide target auditorium and various age groups. To the contrary, application extension "FindTutor-2013", which among other features implements real-time GPS/geolocation info retrieval, which could be potentially interpreted as "personally-identifiable information" and as such, is considered to be a sensitive information, is intended for a more senior auditorium due to Privacy Protection concerns. Please refer to the "User Manual" and "End User License Agreement" (EULA) for more details on this rather important issue, in particular, "Privacy Policy" statement in EULA.

Image 6

Fig. 6: Real-time geolocation features of Ultrabooks

Image 7

Fig. 7: Sample screenshot of the web page w/Bing map showing Tutors nearby

Online Calculators

As mentioned above, Fraction Calculator FC12 has its free online counterpart with limited features placed in public domain. Other computational modules pertinent to this application are also available online at webinfocentral.com. Comparing pros and cons of “both worlds”, i.e. desktop apps vs. online web apps: Edumatter M-12 implemented as regular desktop application for Microsoft Windows does not require live Internet connection and provides much better performance and overall user experience than its online web-based counterparts. On the other hand, it requires one-time product installation and activation on particular client’s computer running Microsoft Windows, while web-based applications are universally accessible via any digital platform equipped with web browser. It's relevant to mention that desktop and web applications are not mutually exclusive, so they can successfully coexist in digital education domain, effectively complementing each other.

References

  1. Fast Integer Algorithms: GCD and LCM (CodeProject article)
  2. Fast Greatest Common Divisor (GCD) Algorithm
  3. Bing Maps Interactive SDK
  4. Geographical distance (wiki)
  5. Great-circle distance (wiki)
  6. Central angle (wiki)
  7. Haversine formula (wiki)
  8. Spherical law of cosines (wiki)

History

  • "Edumatter M12-L" Light" edition v. 8.1.3 has been published on the Intel's AppUp store (11/19/2012)
  • "Edumatter M-12" "Standard" edition v. 8.1.4 has been published on the Intel's AppUp store (11/28/2012)
  • "FindTutor" app extension version 8.1.1 has been published on the Intel's AppUp store (11/26/2012)
  • "Edumatter-814" Standard for Windows 7/8, v. 8.1.4.1 has been released in Aug-2014

License

This article, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)


Written By
Engineer
United States United States
Dr. Alexander Bell (aka DrABell), a seasoned full-stack Software (Win/Web/Mobile) and Data Engineer holds PhD in Electrical and Computer Engineering, authored 37 inventions and published 100+ technical articles and developed multiple award-winning apps (App Innovation Contests AIC 2012/2013 submissions) Alexander is currently focused on Microsoft Azure Cloud and .NET 6/8 development projects.

  1. HTML5/CSS3 graphic enhancement: buttons, inputs
  2. HTML5 Tables Formatting: Alternate Rows, Color Gradients, Shadows
  3. Azure web app: Engineering Calculator VOLTMATTER
  4. Azure: NYC real-time bus tracking app
  5. Quiz Engine powered by Azure cloud
  6. 'enRoute': Real-time NY City Bus Tracking Web App
  7. Advanced CSS3 Styling of HTML5 SELECT Element
  8. Aggregate Product function extends SQL
  9. YouTube™ API for ASP.NET

Comments and Discussions

 
GeneralHappy Ganesh Chaturthi Pin
Ganesh Chaturthi 201421-Aug-14 6:05
Ganesh Chaturthi 201421-Aug-14 6:05 
QuestionDefinitely a 5! Pin
Frank R. Haugen30-May-14 3:43
professionalFrank R. Haugen30-May-14 3:43 
AnswerRe: Definitely a 5! Pin
DrABELL30-May-14 6:23
DrABELL30-May-14 6:23 
GeneralNice Pin
Espen Harlinn30-Oct-12 13:34
professionalEspen Harlinn30-Oct-12 13:34 
GeneralRe: Nice Pin
DrABELL30-Oct-12 14:29
DrABELL30-Oct-12 14:29 
Question[My vote of 1] ??? Pin
Greg Russell8-Oct-12 20:44
professionalGreg Russell8-Oct-12 20:44 
AnswerRe: [My vote of 1] ??? Pin
DrABELL9-Oct-12 3:58
DrABELL9-Oct-12 3:58 
GeneralRe: [My vote of 1] - your justifiable criticsim Pin
Greg Russell9-Oct-12 4:29
professionalGreg Russell9-Oct-12 4:29 
GeneralRe: [My vote of 1] - your justifiable criticsim Pin
DrABELL9-Oct-12 6:30
DrABELL9-Oct-12 6:30 
QuestionFree key Pin
User 69679845-Oct-12 2:44
User 69679845-Oct-12 2:44 
AnswerRe: Free key Pin
DrABELL5-Oct-12 3:25
DrABELL5-Oct-12 3:25 
GeneralMy vote of 5 Pin
devvvy4-Oct-12 21:51
devvvy4-Oct-12 21:51 
GeneralRe: My vote of 5 Pin
DrABELL5-Oct-12 2:18
DrABELL5-Oct-12 2:18 
QuestionHow does this make use of the features of an Ultrabook? Pin
Chris Maunder3-Oct-12 15:42
cofounderChris Maunder3-Oct-12 15:42 
AnswerRe: How does this make use of the features of an Ultrabook? Pin
DrABELL4-Oct-12 14:58
DrABELL4-Oct-12 14:58 
GeneralRe: How does this make use of the features of an Ultrabook? Pin
Chris Maunder5-Oct-12 8:00
cofounderChris Maunder5-Oct-12 8:00 
GeneralRe: How does this make use of the features of an Ultrabook? Pin
DrABELL5-Oct-12 13:02
DrABELL5-Oct-12 13:02 
GeneralRe: How does this make use of the features of an Ultrabook? Pin
Chris Maunder9-Oct-12 13:29
cofounderChris Maunder9-Oct-12 13:29 
GeneralRe: How does this make use of the features of an Ultrabook? Pin
DrABELL9-Oct-12 14:29
DrABELL9-Oct-12 14:29 
GeneralRe: How does this make use of the features of an Ultrabook? Pin
DrABELL5-Oct-12 13:13
DrABELL5-Oct-12 13:13 

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