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

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Linear Programming Constraints and Variables: Definitions and Effects

Classified in Design and Engineering

Written on in English with a size of 2.44 KB

Binding Constraint: LHS equals to RHS at optimal ;  Non-binding constraint: LHS is not equal to RHS at optimal

Shadow Price: Amount by which OFV changes if RHS is increased by one unit

Basic Variable: A decision variable which has non-zero value at optimal ;  Non-basic Value: A decision variable which has a value of zero at optimal

Reduced cost: Amount by which the objective function coefficient needs to be decreased before the variable becomes basic

  • Basic var: "Final Value" >0 and "Reduced cost"=0; With allow inc/dec, optimal solution (Final Value) doesn't change, OFV change by (change)*(Final Value); Beyond allow inc/dec, optimal solution and OFV changes by RESOLVE.
  • Non basic var:  "Final Value"=0 and "Reduced cost"≠0; In a MIN,"Reduced
... Continue reading "Linear Programming Constraints and Variables: Definitions and Effects" »

Port Sizing and Operations: Key Factors and Considerations

Classified in Design and Engineering

Written on in English with a size of 1.81 KB

Port Sizing: Key Factors

Physical Factors

1. Oceanographic and Meteorological Conditions

These conditions define navigational restrictions. Wind conditions are classified as:

  • Soft: Up to 36 kph
  • Moderate: 36 - 63 kph
  • Severe: 63 - 108 kph

2. Vessel Dimensions

Design vessel dimensions (LOA, breadth, freeboard, draft) are crucial for port design.

3. Vessel Maneuverability

  • High: Light war vessels, cruises, bulk carriers, Ro-Ro vessels, first-generation containerships
  • Medium: Modern war vessels, oil carriers (T-2), bulk carriers, second-generation containerships
  • Low: Aircraft carriers, VLCC tankers, third and fourth-generation containerships, older or damaged vessels

4. Vessel Squat

Two main effects:

  • Vertical movement (sinking)
  • Longitudinal rotation

5. Vessel Movements

Tide... Continue reading "Port Sizing and Operations: Key Factors and Considerations" »

Understanding Building Egress Requirements and Components

Classified in Design and Engineering

Written on in English with a size of 3.25 KB

Understanding Building Egress Requirements and Components

  • A means of egress must be an unobstructed path that leads a person safely out of a building. It must meet certain code requirements. Although escalators and elevators are part of general building circulation, codes do not allow them to be means of egress unless very specific requirements are met.
  • There are many situations where egress doors must swing in the direction of travel, e.g., occupant load greater than 49 or in hazardous occupancies. However, if the occupant load is less than 49, the required direction of door swing is not generally specified.
  • The opposite is true. They must be 10 feet wide, or more, to be considered a public way. (Width of an alley or sidewalk)
  • The main difference
... Continue reading "Understanding Building Egress Requirements and Components" »

Comparison of Relational Algebra and Relational Calculus

Classified in Design and Engineering

Written on in English with a size of 1.36 KB

Relational Algebra and Relational Calculus

Relational Algebra and Relational Calculus are the formal query languages for a relational model. Both form the base for the SQL language which is used in most of the relational DBMSs. Relational Algebra is a procedural language. On the other hand, Relational Calculus is a declarative language. Relational Algebra and Relational Calculus can be further differentiated on many aspects, which I have discussed below with the help of a comparison chart.

BASIS FOR COMPARISONRELATIONAL ALGEBRARELATIONAL CALCULUS
BasicRelational Algebra is a Procedural language.Relational Calculus is a Declarative language.
StatesRelational Algebra states how to obtain the result.Relational Calculus states what result we have to
... Continue reading "Comparison of Relational Algebra and Relational Calculus" »

Essential Linux & Git Commands: A Quick Reference

Classified in Design and Engineering

Written on in English with a size of 5.77 KB

Linux

Command

Description

Command

Description

cdChange the current working directory.lsList files and directories.
pwdPrint the current working directory.cpCopy files and directories.
echoDisplay a message.mvMove or rename files and directories.
historyDisplay a list of previously executed commands.rmRemove files.
exitTerminate the current shell session.mkdirCreate a new directory.
typeDisplay information about a command.rmdirRemove a directory.
bgPut a job in the background.catConcatenate and display files.
killSend a signal to a process to terminate it.touchCreate an empty file.
waitWait for a process to complete.chmodChange file permissions.
readRead a line of input from the user.chownChange file ownership.
printfFormat and print a message to the console.
... Continue reading "Essential Linux & Git Commands: A Quick Reference" »

Digital Marketing and Web Development Fundamentals

Classified in Design and Engineering

Written on in English with a size of 6.17 KB

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
... Continue reading "Digital Marketing and Web Development Fundamentals" »

The Importance of Service Environment in Shaping Customer Experience

Classified in Design and Engineering

Written on in English with a size of 1.85 KB

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" »

Structural Analysis: Thermal Loads and Flexible Supports in Force Method

Classified in Design and Engineering

Written on in English with a size of 2.94 KB

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 = tC – t0.

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

t0 - the beginning temperature in The element.

αt –thermal expansion ratio.

Ni – the values of axial forces in The elements under the unit force Xi.

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

Where:

Δt – is Calculated: Δt = tu – td.

αt – thermal expansion ratio.

h – a height of element cross-section.

Mi – the values of moments in the Elements under the unit force Xi.

14. Flexible

... Continue reading "Structural Analysis: Thermal Loads and Flexible Supports in Force Method" »

Network Design Optimization: Core Node Placement Model

Classified in Design and Engineering

Written on in English with a size of 3.49 KB

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

... Continue reading "Network Design Optimization: Core Node Placement Model" »

City Service Exception Tests

Classified in Design and Engineering

Written on in English with a size of 4.39 KB

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" »