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Words 3990

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In this era of information technology, civil engineers rely heavily on software to perform their design tasks. Unfortunately, most commercial structural analysis packages are closed-source, which means that the operations that the program performs cannot be inspected by the user.

Moreover, such software packages are invariably very pricey, and, hence, are generally not affordable for students and smaller engineering firms.

The objective of this design project was to design a structural analysis program that would be free of charge and available to all. This computer program was to be open source and well commented, so that its users could comprehend the operations performed in the analysis of a given structure.

To accomplish these objectives, the generalized stiffness method of structural analysis was implemented into a computer algorithm. This algorithm, called “TrussT Structural Analysis”, is a collection of visual basic modules embedded in a Microsoft Excel document using Visual Basic for Applications (VBA). This design report outlines the theory behind TrussT Structural

Analysis, as well as the methods by which that theory was implemented into computer algorithms. The first two sections of this report present the theory of the generalized stiffness method of structural analysis and its implementation into a computer algorithm. The following sections present the procedures by which the stiffness method was modified to incorporate the analysis of structure with special characteristics such as member applied loads, member releases or support settlements. A computer implementation of the Euler method of analysis is described to account for the geometric non-linearity of structures. Finally, algorithms that can generate member force diagrams and moment diagrams are presented.

2.0 Generalized Stiffness Method

The term stiffness refers to a body’s ability to resist imposed displacements by generating internal forces. Conversely, the term flexibility refers to a body’s ability to deflect when subjected to

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applied forces. These two terms are analogous to two methods of structural analysis: the flexibility method, which generates compatibility equations to solve for forces, and the stiffness method, which generates equilibrium equations to solve for displacements. The preliminary report done in Phase I of this project outlined the reasons why the stiffness method is more suitable to computer implementation than its counterpart. The computer algorithm presented in this report was designed based on the stiffness method of structural analysis.

The stiffness method is based on the fundamental equilibrium equation shown in Equation 1. (1)

This equation equates force (P) to the product of stiffness (KK) and displacement (d). In the simplest terms, this equation represents the equilibrium between external forces and internal forces. In terms of a structure, the applied joint forces (P) and joint displacements (d) are vectors, whereas the structure stiffness is expressed as a matrix of n-by-n terms, n being the degrees-of-freedom of that structure. Generally, both the applied forces (P) and the structure’s stiffness (KK) are known, which leads to a system of n equations with n unknown joint displacements (d).

3.0 Computer Implementation of the Stiffness Method

The analysis engine driving TrussT Structural Analysis is a computer implementation of the stiffness method. This section describes the basic approach that was taken to implement the stiffness method in a computer program. That implementation as utilized in TrussT Structural

Analysis is illustrated in Figure 1.

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Obtain Input Parameters

Organize Inputs in Arrays

(Record Keeping)

Calculate Member Stiffnesses (s)

Assemble Global Stiffness Matrix (K)

Solve for Global Displacements (d)

Transform Displacements to

Local Coordinates (u)

Calculate Member Forces (Q)

Transform Member Forces to

Global Coordinates (F)

Assemble Reaction Forces (R)

User Inputs

Joint

Displacements

Reaction

Forces

Figure 1: Analysis Procedure Flow Chart

3.1 Input

TrussT Structural Analysis requires information about the structure to be inputted by a user in three parts: joint inputs, member inputs, and load inputs. Appendix A of this report presents a user’s manual, which outlines how to use the program and input the necessary variables.

The variables required by the program to analyse a structure are described in following subsections. Consistent units must be used when inputting information in the user interface.

Although the user interface suggests the metric units of mm, kN and GPa, any set of consistent units will produce correct results (e.g. in, kips and ksi).

3.1.1 Joint Inputs

For each joint, the program requires:

Joint Coordinates - numerical values for the three dimensional coordinates (x, y, z).

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Joint Boundary Conditions – indicating whether translations and rotations are free or restrained along the x, y, and z axes. Alternatively, the user can specify whether a joint is fixed, pinned or free.

3.1.2 Member Inputs

For each member, the program requires:

Member Joints - the two joints the member spans.

Member Orientation (ψ) – defined as either (1) for general members or (2) for vertical members. (1) The angle, measured clockwise positive, when looking in the negative x direction, through which the local xyz coordinate system must be rotated around its x-axis so that the xy plane is vertical with the y-axis pointing upwards.

(2) The angle, measured clockwise positive, when looking in the negative x direction, through which the local xyz coordinate system must be rotated around its x-axis so that the z axis is parallel to, and points to global z.

Member Section Properties – modulus of elasticity E, area A, shear modulus G, moment of inertia about the strong axis Iz, moment of inertia about the weak axis Iy, and the torsion constant J.

3.1.3 Load Inputs

For each load the program requires the:

Load Location – the joint on which an external load is applied.

Load Magnitude – numerical value of the load (force and moment) in each axis.

3.2 Record Keeping

In order to organize adequately all the input and output information in a set of matrices, the program assigns record-keeping indices to every joint translation and rotation. These indices, later referred to as codes, represent the position of a certain joint displacement or reaction in the

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global vectors and matrices presented in Equation 1. In three dimensions, each joint has six possible movements (translations and rotations about each of the x, y, and z axes). The computer program first assigns codes to the joint movements that are free, that is, joint movements that are not boundary conditions. The total number of such movements is referred to as the degrees-offreedom of the structure. Once all the degrees-of-freedom have been assigned codes, the computer program then assigns codes to the joint movements with boundary conditions.

3.3 Member Stiffness

Based on the inputted member properties, the program generates a 12 x 12 member stiffness matrix (s ss) and transformation matrix (T TT) for each member. Equation 2 illustrates the local stiffness matrix for a space frame element based on the member properties, while Equation 3 shows the transformation matrix required to transform the member’s stiffness matrix into the structure’s coordinate system.

(2)

(3)

…where (rrr) is given by Equation 4 for general members and by Equation 5 for vertical members.

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(4)

(5)

The member stiffness matrix (s ss) for each member is converted from the Local Coordinate

Systems (LCS) into the Global Coordinate System (GCS) through Equation 6, which yields the member stiffness matrix in the GCS (k kk). k (6)

3.4 Global Stiffness

A structure’s global stiffness (KK) consists of a n-by-n matrix of coefficients, where n represents the degrees-of-freedom of the structure. To assemble (KK), the program uses the codes assigned in the record keeping phase to assemble the individual member stiffness matrices to the global stiffness matrix.

3.5 Determining Displacements

The joint displacements at the free degrees-of-freedom (d) are computed using the joint equilibrium equation, Equation 1, which relates these displacements to the known applied joint loads vector (P) and to the known structure’s global stiffness (KK). A Gauss-Jordan solver is used to solve for these member displacements.

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3.6 Converting Displacements to Local Coordinates

Once the displacements in the GCS (d) are determined, they are stored as the member end displacements (v) using the record keeping codes. These global displacements are then converted to the LCS through the member transformation matrices, as shown in Equation 7. (7)

3.7 Calculating Member Forces

Once the joint local member displacements (u) are known, the algorithm calculates the member forces (Q) based on the member’s local stiffness matrix (s ss) with Equation 8. Equation 8 is the member-space equivalent of the basic equilibrium equation, Equation 1. (8)

3.8 Transformation of Member Forces

The member forces in LCS (Q) are transformed back to the GCS using Equation 9, at which point they are assembled based on the structure’s configuration (using the record keeping codes) to obtain the global reactions. (9)

3.9 Computer Algorithm

The following pseudo-code outlines the stiffness method presented in this section to solve for a framed structure under joint loads. The nomenclature of the variables and the procedures used are described following the code.

'Assembly of Applied Loads Vector (P)

Loop i = 1 To numNodes

M1() = GetCodes(Node(i))

M2() = GetForces(Node(i))

Loop j = 1 To 6

P(M1(j)) = M2(j)

End Loop

End Loop

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‘Assembly of Member Stiffness Matrix (S) and Transformation Matrix (T); Performed in Member Class

Module for each member

S_local() = MemberStiffness(E, A, L, Iy, Iz, J)

T() = Transformation(x1, x2, y1, y2, z1, z2)

S_global() = Transpose(T()) * S_local() * T()

'Assembly of Structure’s Stiffness Matrix (K)

Loop i = 1 To numMem

M1() = GetCodes(Member(i))

M2() = GlobalStiffness(Member(i))

Loop j = 1 To 12

If M1(j) minDOF Then

P(M1(j)) = P(M1(j)) + M2(j)

End If

End Loop

End Loop

Description of Variables and Procedures

M1() - Temporary matrix

M2() - Temporary matrix numNodes – Number of nodes in the system numMem – Number of members in the system

S_local() - Local member stiffness

S_global() - Global member stiffness matrix

K() - Structure’s overall stiffness matrix

Kff() - Structure’s partitioned stiffness matrix for free nodes

E, A, Iy, Iz, J – Member properties specified by the user

L – Member length

T() – Member transformation matrix x1, x2, y1, y2, z1, z2 – Member coordinates minDOF – Number of degrees-of-freedom in the system

P() - Joint forces vector

Q() - Member forces vector in local coordinates

F() - Member forces vector in global coordinates u() - Nodal displacements vector in local coordinates

D() - Nodal displacements vector in global coordinates

Node(i) - Class module for node i

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Member(i) - Class module for member i

Getcodes - Invokes code number stored in the class module.

GetForces - Invokes user-specified load stored in the class module.

MemberStiffness - Calculates the member stiffness matrix using Equation 2.

Transformation - Calculates the member transformation matrix using Equation 3.

MemberStiffness - Invokes the member stiffness in the global coordinate system stored in the class module.

MemberForce - Invokes the member forces stored in the class module.

Transpose - Performs transposed matrix operation.

MatInv - Performs inverse matrix operation.

4.0 Equivalent Joint Loads

As the basic stiffness method considers only loads applied at the joints, the concept of Equivalent

Joint Loads (EJL) can be used to expand the scope of the stiffness method to include member loads. To determine the EJL of a structure, the EJL of each member must be determined and assembled using the record-keeping codes. Kassimali [1] and others have shown that these EJLs are equivalent to the negative of the fixed-end forces generated by a set of loads on a fully fixed member. Fixed-end forces for a member subjected to any set of loads can be found based on the already derived formulae found in many structural analysis textbooks, such as Kassimali [1]. The equations used in TrussT Structural Analysis to solve for the fixed-end forces are included in

Appendix B. TrussT Structural Analysis has the capability of converting member point loads and linearly variable distributed loads to equivalent joint loads. No formula could be found in available literature that described the fixed-end forces caused by a linearly variable axial load.

Therefore, a formula was derived for linearly variable axial loads based on the axial point load formula presented by Kassimali [1]. The derivation of this can be found in Appendix B.

The fixed-end forces are assembled from local coordinates (Qf) to global coordinates (Pf) using the same coding mechanism used to assemble the structure’s stiffness matrix.

The equivalent joint loads are incorporated in the procedure described in section 3 by subtracting the fixed-end forces (adding the EJL) from the applied joint loads. This operation is integrated into the analysis by modifying Equations 1 and 8 to Equations 10 and 11. (10) (11)

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The following pseudo-code illustrates the conversion of member loads to equivalent joint loads in

TrussT Structural Analysis.

If bDist = False Then

R() = PointLoad(L, Pos, sForces(3))

EJL(3) = EJL(3) + R(1)

EJL(5) = EJL(5) + R(2)

EJL(9) = EJL(9) + R(3)

EJL(11) = EJL(11) + R(4)

R() = PointLoad(L, Pos, sForces(2))

EJL(2) = EJL(2) + R(1)

EJL(6) = EJL(6) + R(2)

EJL(8) = EJL(8) + R(3)

EJL(12) = EJL(12) + R(4)

R() = AxialLoad(L, Pos, sForces(1))

EJL(1) = EJL(1) + R(1)

EJL(7) = EJL(7) + R(2)

R() = Moment(L, Pos, sForces(6))

EJL(2) = EJL(2) + R(1)

EJL(6) = EJL(6) + R(2)

EJL(8) = EJL(8) + R(3)

EJL(12) = EJL(12) + R(4)

R() = Moment(L, Pos, sForces(5))

EJL(3) = EJL(3) + R(1)

EJL(5) = EJL(5) + R(2)

EJL(9) = EJL(9) + R(3)

EJL(11) = EJL(11) + R(4)

R() = Torque(L, Pos, sForces(4))

EJL(4) = EJL(4) + R(1)

EJL(10) = EJL(10) + R(2)

Else

R() = Distributed(L, Pos1,Pos2, sForces(5), sForces(6))

EJL(3) = EJL(3) + R(1)

EJL(5) = EJL(5) + R(2)

EJL(9) = EJL(9) + R(3)

EJL(11) = EJL(11) + R(4)

R() = Distributed(L, Pos1,Pos2, sForces(3), sForces(4))

EJL(2) = EJL(2) + R(1)

EJL(6) = EJL(6) + R(2)

EJL(8) = EJL(8) + R(3)

EJL(12) = EJL(12) + R(4)

R() = AxialDistributed(L, Pos1, Pos2, sForces(1), sForces(2))

EJL(1) = EJL(1) + R(1)

EJL(7) = EJL(7) + R(2)

End If

Description of Variables and Procedures bDist - Identifier for distributed loads sForces() - Member load vector

( sForces(1) = Fx; sForces(4) = Mx for point loads )

( sForces(1) = Fx1; sForces(2) = Fx2 for distributed loads )

L - Member length

Pos - Location of point load

Pos1 – Location of near-end distributed load

Pos2 – Location of far-end distributed load

R() – Temporary matrix to store computed equivalent joint load for the member load being considered.

EJL() – Equivalent joint load vector

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PointLoad - Converts point member load to equivalent joint load.

AxialLoad - Converts point axial load to equivalent joint load.

Moment - Converts applied moment to equivalent joint load.

Torque - Converts torque to equivalent joint load.

Distributed - Converts distributed load to equivalent joint load.

AxialDistributed - Converts distributed axial load to equivalent joint load.

*Equations used for the above sub-function are included in Appendix B

5.0 Member Releases

TrussT Structural Analysis has the ability to account for member releases in a structure. A member is said to be released at a certain location when its ability to develop an internal force at that location has been removed. Physical examples of member releases are hinges (rotational releases) and slotted connections (translational releases). Figure 2 depicts the possible locations of member releases on a space frame member.

Figure 2: Possible Locations of Member Releases

Releases at intermediate locations along the member can also be modeled using the approach outlined below by utilizing two smaller members and releasing the joining ends.

To account for a member release, one must modify the basic equilibrium equations to ensure that the force at the location being released is zero. That is, if one is to release the translation at #3, then the internal force Q3 in Equation 11 must be set to zero. Setting Q3 equal to zero implies that the right-hand side of the Q3 equilibrium equation is also zero, as shown in Equation 12. (12)

Equation 12 shows that there is inter-dependence between the set of member displacements.

Equation 12 can therefore be re-written as Equation 13. … / (13)

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The stiffness matrix needs to be modified to reflect the physical reality of the member release.

Given that Q3 = 0, any set of displacements (u) will cause Q3 to remain 0. Therefore, the third row of the member stiffness matrix should be a row of zeros. As Equation 14 shows, the equilibrium conditions now consist of 11 equations containing 12 unknown displacements.

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(14)

Given that there is one too many unknowns for this system of equations to be solvable, the displacement u3 must be distributed to the other displacements according to Equation 13.

Additionally, as Equation 13 shows, the released displacement u3 also depends on Qf3, the member local fixed-end force at location #3. Therefore as u3 is being substituted into the other rows of the stiffness matrix, the fixed-end forces corresponding to this row must also be modified according to Equation 12.

The final element stiffness matrix will be an 11 x 11 matrix. This released matrix can also be thought of as a 12 x 12 matrix with a row and column of zeros. The row of zeros signifies that no force can be generated at that location regardless of the member displacements, and the column of zeros is necessary to have a solvable system of equations. The effect of that displacement has been expressed as a sum of other displacements and fixed-end forces, and the stiffness and member fixed-end forces coefficients have been modified accordingly.

The following procedure is analogous to how TrussT Structural Analysis implements the member release procedure.

1. Determine location to be released (r)

2. Express ur as the sum of other displacements:

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3. For every ij element of the stiffness matrix, subtract the following stiffness according to

Equation 12:

4. Similarly, for the each i fixed-end force, subtract the following force according to

Equation 12:

5. Set all ri elements of the stiffness matrix equal to zero: 0

6. Set all ir elements of the stiffness matrix equal to zero: 0

The complete algorithm for this process can be found in the cMember class module of the program code, under the sub-procedures ReleaseMatrix and ReleasedQF. TrussT Structural

Analysis uses the above procedure to transform the space frame stiffness matrix into various released matrices. Instead of having different algorithms to solve for the displacements of trusses, beams or other simplified structures, TrussT uses member releases to transform the space frame stiffness matrix to the desired simplified matrix. As Equation 15 shows, a space frame stiffness matrix released 10 times at r = 2, 3, 4, 5, 6, 8, 9, 10, 11, and 12 is equivalent to a 2 x 2 axial member stiffness matrix.

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(15)

6.0 Support Settlement

The alternative formulation of the stiffness method, as presented by Kassimali [1], is particularly well suited to the incorporation of a support settlement into the analysis of a structure. This method involves assembling a global stiffness matrix (KK* **) of size m-by-m, where m represents not only the quantity of degrees-of-freedom, but the total quantity of degrees in the structure.

This method also involves assembling an m sized applied load vector (P*), fixed-end forces vector (Pf*) and global displacement vector (d*). The resulting equilibrium is shown in Equation

16.

(16)

Equation 16 is particular in the way that it has unknowns on both sides of the equation. To solve such a system, Kassimali’s proposed partitioning the KK* ** matrix into four sub-matrices and partitioning the P*, Pf* and d vectors into two sub-vectors each as follows:

(17)

(18)

(19)

(20)

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…where dR is the vector of known support settlement and PR is the vector of unknown applied loads (support reactions).

The KK and KKF FFR RR sub-matrices are used to compute the joint displacements (d) as per Equation 21, whereas the KKR RRF FF and KKR RRR RR sub-matrices are used to compute the unknown reactions forces (PR) as per Equation 22. (21) (22)

Although this formulation requires larger matrices, it allows for the unknown global reactions to be solved directly, without using the assembly process described by Equation 9.

One drawback of this method of analysis arises when conducting second-order analyses (as discussed in Section 7). Since second-order analyses required the computation of the member forces, it was found not to be computationally advantageous to compute reaction forces as per

Equation 22. Second-order analyses require that the systems of equations be solved numerous times, therefore the reduction of the number of operations within the loop of iterations will drastically reduce the overall computation time.

For that reason, a hybrid between Kassimali’s alternative formulation and the original formulation was adopted by TrussT Structural Analysis, whereby the global displacements are computed by Equation 21, and the support reactions are computed as before, by assembling the member forces (F). Therefore, Equation 22 is not utilized in the TrussT Structural Analysis algorithm. It should be noted that a structure with no support settlement has a (dR) displacement vector of 0; therefore, Equation 21 reverts to its original form in Equation 10.

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7.0 Second-Order Analysis

In first-order analysis, it is assumed that the load-displacement relationships of structural elements are linear, such that the linearly-assumed displacements under an increasing applied load (P) will deviate from the actual displacement, as shown in Figure 3.

Figure 3: Equilibrium Paths of Linear and Nonlinear Analyses

As Figure 3 illustrates, the discrepancy between the assumed displacements and the actual displacements grows enormously as the applied load increases.

Second-order analysis involves continuously or intermittently changing the stiffness of a structure so that it responds to applied loads based on its current configuration, rather than based on its initial configuration. This procedure more accurately models the displacement behaviour of an element. TrussT Structural Analysis has a function that incorporates geometric nonlinearity into the analysis. The algorithm is based on the Euler method, also known as the incremental single-step method. The Euler method is the most elementary second-order analysis method; however, it is suitable for solving a system with moderate nonlinearity, which applies to most structural engineering applications. Figure 4 illustrates an element equilibrium path using second-order analysis based on the Euler method alongside the actual equilibrium path.

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Figure 4: Euler method second-order iteration

As Figure 4 illustrates, the actual equilibrium path of an element is more accurately modelled with the Euler method than with first-order analysis. Furthermore, as the number of iterations increases, the linear segments outlining the equilibrium path will become shorter and the accuracy of the model will increase.

In the program, once the user chooses to perform a second-order analysis, the user may also specify the number of iterations (n). The prescribed loads are then discretized into n incremental loads (ΔP). The program performs n linear analyses that are analogous to the first-order analysis, described in sections 2 and 3, to calculate the incremental displacements (Δu) and the member forces (ΔQ). The second-order analysis is different from the first-order analysis in the sense that it uses the tangent stiffness matrix (Kttt), which is the sum of the elastic stiffness matrix (K) and the geometric stiffness matrix (Kggg). The member geometric stiffness matrix is given in Equation

23.

22

(23)

As shown in Equation 23, the member geometric stiffness matrix is a function of the member axial force (Fx2), hence, the geometric stiffness (and the tangent stiffness) will change as the nodal displacements change along the iteration. Once the iteration is complete, the calculated incremental displacements and member forces…...

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...object composition than class inheritance.as that happens,emphasis shifts away from hard-coding a fixed set of behaviors toword defining a smaller set of fundamental behaviours that can be composedinto any no. of more complex onces.thus creating objects with perticular behaviour requires more than simply instantiating a class. Design patterns “Each pattern describes a problem which occurs over and over again in our environment, and then describes the core of the solution to that problem, in such a way that you can use this solution a million times over, without ever doing it the same way twice.” [Christopher Alexander] Design patterns capture the best practices of experienced object-oriented software developers. Design patterns are solutions to general software development problems. A pattern has four essential elements * Pattern Name * Problem * Solution * Consequences Pattern Name: Is a handle we can use to describe a design problem, it’s solutions & consequences in a word or two. Naming a pattern immediately increases our design vocabulary. It lets us design at a higher level of abstraction. Problem: It describes when to apply the pattern. It explains the problems and it’s context. It might describe specific design problems such as how to represent algorithms as objects. It might describe class or object structures that are symptomatic of an inflexible design. Solution: Describes the elements that make up the......

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...Structural theories One of the theories is Marxism who studies society on a macro perspective so they generate a lot of statistics. They concentrate a lot on class and believe there is conflict between two opposing classes’ bourgeoisie and working class. They have a similar view to the social action theory and that view is in society there is struggle between the powerful and the powerless. They also have a view on feminism and that is it’s not just men who exploit women but also capitalist. Their view is capitalism is the root of all exploitation which also creates competition between social classes. They have views on the role of the family and they believe family maintains capitalism. They have a very strong opinion on school and believe education reproduce a passive workforce for capitalism as in students are taught workers should accept their position and that causes less conflict for the capitalists. They also believe education creates class inequality as in upper class are meant to succeed whilst lower class are meant to fail. They believe school is just preparation for the work force as in the rules students are told follow. This creates ideological dominants by the school as they promote the rich stay rich and the poor stay poor. They also believe that education reproduces the public structure. The Marxist theory has been criticised by other theories which is typical in sociology. Functionalists believe they focus too much on class and need to look more at......

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...Structural family therapy (SFT) is a method of psychotherapy developed by Salvador Minuchin which addresses problems in functioning within a family. Structural Family Therapists strive to enter, or "join", the family system in therapy in order to understand the invisible rules which govern its functioning, map the relationships between family members or between subsets of the family, and ultimately disrupt dysfunctional relationships within the family, causing it to stabilize into healthier patterns.[1] Minuchin contends that pathology rests not in the individual, but within the family system. SFT utilizes, not only a special systems terminology, but also a means of depicting key family parameters diagrammatically. Its focus is on the structure of the family, including its various substructures. In this regard, Minuchin is a follower of systems and communication theory, since his structures are defined by transactions among interrelated systems within the family. He subscribes to the systems notions of wholeness and equifinality, both of which are critical to his notion of change. An essential trait of SFT is that the therapist actually enters, or "joins", with the family system as a catalyst for positive change. Joining with a family is a goal of the therapist early on in his or her therapeutic relationship with the family. Structural and Strategic therapy are important therapeutic models to identify as many therapists use these models as the bases for treatment. Each......

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... Forgiveness therapy focuses on resentment, which can lead to depression, anxiety, and other negative psychological outcomes (). Based on the material that this writer has read, forgiveness is a decision to give up resentment and to be able to set aside selfishness, and to be able to acquire a sense of peace to move forward in their lives without reconciling with the person which abused them. There were 20 women ranging from 30 to 54 who had been psychologically abused, which participated in a research study. To be eligible to participate in this study, the woman had to have been emotionally abused, they had to be divorced or either separated permanently from their partner for at least 2 years. These woman ranged in race, ethnicity, education and work background. By participating in this study, Enright and Reed (2006) thought that if women used the forgiveness techniques they would see a decrease in depression, anxiety, and post-traumatic stress and an increase in her self-esteem and decision making process. Reflection...

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...HACKING SECRETS REVEALED Information and Instructional Guide HACKING SECRETS REVEALED Production of S&C Enterprises T able of Contents Disclaimer Introduction i Trojans Joiners ICQ CHAPTER 1 1 Chapter 6 Access Granted CHAPTER 2 1 15 18 18 19 19 19 19 CHAPTER 7 42 43 44 45 49 55 59 Bank Account Information Email Pictures Resume Survellance Via Internet Connection 36 37 39 39 39 40 29 34 34 System Intrusion in 15 Seconds The Trojan Horse The Hack NewsGroups Grapevine Email Un-Safe Websites IRC ChatSites CHAPTER 3 20 20 Acceptable Files Readme & Text Files How To protect Yourself Firewalls Antivirus Software Tips & Tricks Protecting Shared Resources Disabling File and Printer Sharing Oh No My system's Infected Chapter 4 Who are Hackers Anarchist Hackers Hackers Crackers 24 24 25 26 Chapter 8 Every Systems Greatest Flaw Chapter 9 How to Report Hackers 65 60 Chapter 5 Tools of the Trade Portscanners 27 28 Chapter 10 Final Words 74 DISCLAIMER The authors of this manual will like to express our concerns about the misuse of the information contained in this manual. By purchasing this manual you agree to the following stipulations. Any actions and or activities related to the material contained within this manual is solely your responsibility. The misuse of the information in this manual can result in criminal charges brought against the persons in question. The authors will not be held responsible in the event any criminal charges be brought against any......

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...Principle of Software Engineering Table of Contents Abstract 3 Introduction 4 Boehm's First Law 4 Boehm's Second law 5 Conway's law 5 Parnas Law 6 Corbató Law 7 Observation 8 Theory 9 Law 9 Question 3 10 Law 11 References 12 Abstract The purpose of the study is to show the capability to understand the set of laws that are the part of principles of the software engineering. In this paper, it is discussed that there are many laws related to the software engineering but only few of them are to be addressed. Boehm first and second law, Conway’s laws, Parnas laws & Corbato law were discussed with examples. There are two relationship processes that are also discussed, related to the software Engineering. Law method and tools which are depended on each other and they are performing the task with the help of principle and process by following the rules. Same scenario is followed in other relation too, where observation, law and theory are depended on each other. Observation is repeatable to law and law is explained by theory. Theory should be confirmed by the law and it predict by the observation before further proceeding. Introduction Question No 1 Boehm's First Law Errors are more regular in the middle of fundamentals and configuration exercises and are more abundant when they are displaced. In this law, some basic configuration errors do outnumber code blunders. However, cost stays......

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...Identify two periodical publications that focus on software architecture (either solely or partly). Submit the following information: publication name, URL, publisher name, & the year it was first published. IEEE Potentials, First Publication Year: 1982 URL : http://ieeexplore.ieee.org/xpl/mostRecentIssue.jsp?punumber=45 Publisher Name: IEEE Xplore Msdn magazine First Publication Year: 2001 URL: http://msdn.microsoft.com/en-us/magazine/dn973005.aspx Publisher Name: The Microsoft journal for developers Write a half-page short essay comparing and contrasting software architects and software engineers. Software architect has responsibility for guaranteeing coherence of all aspects of the project as an integrated system. Architect answerable for overall technical quality, developer for lower implementation selections. The architect holds the futuristic views and proactively sees the system before it\'s designed, being the holder of the vision. Software architect focuses on money and also the disposition and drive to guide individuals. a leader who will apply/share their broad framework. Pragmatic handling of the technical solution and act with the business in addition as the techies, marketing the vision to each. A software architect has the vision to own the most effective style ideas. Architects will see each micro and macro (inwards and outward) whereas engineers see small and outwards and want to be carried by the architect to examine macro/outwards. Maintaining...

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