Notes, abstracts, papers, exams and problems of Design and Engineering

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.

Linux

a structure is called statically indetermined if there is at least one load for which the external and internal reactions can be comptuted from the psequilibrium equation but not uniquely.

PS. A satically determined structure obtained from the original one by removing. N constraints and introducing the corresponding force/moments as redundants (Xi, i=1,2,...N)

Flexibility coeff. Aij is the displacement in the line of Xi due to Xgorritoj=1

Stiffness coefficients aij unbalanced force/moment at the ith artificial constraint due to a unit displacement applied at the jth artificial constraint

Load constants ai0 unbalanced force/moment at the ith artificial constraint due to the action of the given loads a0

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" »

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" »

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" »

Stages of Language Acquisition in Children

1. The Prelinguistic Period

1.1. Babbling

In auditory perception for speech, maturity is reached between 8 and 10 months when the restriction to the native language's phonology is observed. From the point of view of articulation, babies have a structure and motor control of the orophonation that will undergo very substantial changes in the early years and during the change of adolescence to reach the maturity of adults. It is clear that babies cannot produce all the sounds they can distinguish. Sounds as seemingly simple as vowels are difficult to produce by newborns since the space available for any movement of the tongue produces a constriction. This occurs during the first months when most of the sounds... Continue reading "Child Language Acquisition: 5 Stages of Development" »