Notes, summaries, assignments, exams, and problems for Design and Engineering

Industrial Control Systems Fundamentals

PLC and Control Logic Principles

• ON/OFF Control: Always oscillation is true.
• PNP Digital Input: Normally closed switch logical value 0 is true.
• PLC Architecture: Two basic forms are block/compact I/O and rack/modular mount I/O (true).
• Transistor PLC Outputs: Provide low electrical power at high frequencies (100Hz) is true.
• Electrical Wiring: Systems perform real-time control of industrial processes (true).
• Proportional Control: Ability to eliminate steady-state error is false.
• Memory Storage: User programs are loaded into PLC ROM memory (true).
• NC Control: Controls several parameters, including servomotor current (true).
• PLC Digital Inputs: High-frequency binary signals (≥1KHz) is false.
• Programming Standards:

Assumptions of Direct Displacement Method

The effect of elongation or reduction of a component is omitted as negligible, except where it is decisive (such as thermal loads, shrinkage, or when the component is a tie-bar or tie-rod).

The difference between the length of a deflected component and the length of its chord is omitted because of the relatively very small real movement of the component nodes.

The effect of lateral and axial forces (V, N) is usually omitted.

The degree of kinematic indeterminacy is the sum of possible rotations of rigid nodes and independent movements of any nodes.

Kinematic Indeterminacy and Formulas

The degree of kinematic indeterminacy is the sum of possible rotations of rigid nodes and independent movements of any nodes.... Continue reading "Direct Displacement Method in Structural Analysis" »

Digital Marketing (DM)

Overview

DM promotes brands through digital channels globally, offering targeted, personalized, cost-effective, and measurable marketing solutions.

Changes in E-commerce

Before

• Audience and medium-centered
• Periodic updates
• Scarcity of information
• Stages & consent-driven interactions
• Unidirectional communication
• Focus on information dissemination

Now

• User-centered
• Multimedia content
• Content-centered
• Real-time updates
• Abundance of information
• Hypertext navigation
• Knowledge sharing
• Two-way communication

Four DM Strategies

1. Database Marketing (DB): Designing and communicating the brand (e.g., Coca-Cola) to increase engagement, enhance customer experience, and cater to both old and new customers.
2. Customer Experience Design (CXD): Providing the

Phys Evidence - Serv Envirom

(Important element of service mark mix) Service environment relates to style and appearance of physical surroundings and other elements by custom designing. Service environment is an art, involves time, effort, and can be expensive.

Purpose of Service Environment: Shape customer's experience and behavior, signal quality and position, differentiate and strengthen brand, core component of value position, facilitate service encounter.

Servicescape Model

Model developed by MaryJo Bitner. An important contribution of Bitner's is the inclusion of employee responses to service environment. Internal customer and employee responses can be cognitive, emotional, or physiological responses. Dimensions of service environment include... Continue reading "The Importance of Service Environment in Shaping Customer Experience" »

13. Thermal loads in Force Method.

Due to the change Of the temperature into the element the displacement of the structure is Described the following formula:

Where:

t – Is calculated: t = t_C – t₀.

t_C - current temperature in the Element at the centroid of element cross-section.

t₀ - the beginning temperature in The element.

α_t –thermal expansion ratio.

N_i – the values of axial forces in The elements under the unit force X_i.

Due to the temperature Difference around the element the displacement of the structure is Described the following formula:

Where:

Δt – is Calculated: Δt = t_u – t_d.

α_t – thermal expansion ratio.

h – a height of element cross-section.

M_i – the values of moments in the Elements under the unit force X_i.

14. Flexible

Optimization Problem Setup and Initialization

The following code initializes parameters and sets up the optimization problem structure using Net2Plan's framework.

Initialization of Parameters and Variables

final double C = Double.parseDouble(algorithmParameters.get("C"));
final int K = Integer.parseInt(algorithmParameters.get("K"));
netPlan.removeAllLinks();

OptimizationProblem op = new OptimizationProblem();
final int N = netPlan.getNumberOfNodes();

// Decision Variables
op.addDecisionVariable("z_j", true, new int[] {1, N}, 0, 1); 
// z_j: 1 if location j has a core node (Array of N positions)

op.addDecisionVariable("e_ij", true, new int[] {N, N}, 0, 1); 
// e_ij: 1 if access node at location i is connected to a core node in j

Defining Input

TESTCANCEL

EXCEPTION expected

• Service already cancelled, we capture and check text before throwing the exception
• @throws CityServiceException

@Test(expected = CityServiceException.class)

public void testAssignExceptionText () throws CityServiceException {

Activity a = moderator.cancel(service, "already exists");

assertNotNull(a);

try {

moderator.cancel(service, "reported by another user");

}

catch (CityServiceException e) {

assertEquals("Service was already cancelled", e.getMessage());

throw e;

}

//fail

fail();

}

TESTCOMMENT

EXCEPTION expected

• User not found. The user is not found, we capture and check text before throwing the exception
• @throws CityServiceException

@Test(expected = CityServiceException.class)

public void testUserNotFoundCheckText () throws CityServiceException... Continue reading "City Service Exception Tests" »

Mandelbrot Set Iteration with Higher Powers

The Mandelbrot set calculation, specifically for z_n+1 = z_n⁶ + c, involves generating a grid of points in the specified complex plane and determining the associated c value (simply x + iy).

Initialization and Divergence Loops

Initialize matrices for the iterated value (z) and the number of iterations before blowing up (k). Everything will be done at once in a single while loop. This loop iterates the grid and checks for divergence, stopping once N reaches N_max.

Any k locations for which abs(w) > maxZ at this previous iteration are assigned the value of N, which indicates the rate of divergence and is used for color coding. If any k values are equal to 0, set them to the final iteration number. Write... Continue reading "Fractal Generation and Numerical Methods in MATLAB" »

Translation of Axis

When you need to simplify equations, mainly the conics (circumference, parabola, ellipse, and hyperbola), you need to create a pair of coordinate axes parallel to the originals. This enables working with equations more simply.

This creation of axes is known as parallel translation of axes and consists of moving one or both axes so that the origin moves to a new position, and the axes are parallel to the original.

In the following figure, you can see how you can translate the equations of the curves from one Cartesian plane x and y to a Cartesian plane x’ and y’.

The new origin O’ is defined, and the axes x’ and y’ are parallel to the original axes x and y, so that for a point P(x,y) you have P(x’,y’). With this,... Continue reading "Axis Translation and Rotation: Simplifying Conic Equations" »