Notes, summaries, assignments, exams, and problems for Mathematics

What is a One-Way Function?

A one-way function is a function that is easy to compute in one direction but difficult to compute in the reverse. For example, given an input, a hash is easy to compute. However, given the output, it is extremely difficult (time-consuming) to determine the input.

What is a Trapdoor Function?

A trapdoor function is like a one-way function; however, a trapdoor function can reverse the one-way function if the trapdoor is known. For example, finding the two prime divisors of 6,895,601 is difficult. However, if you know that 1,931 is one of the numbers, it will be easy to divide 6,895,601 by 1,931 to determine the answer. In this case, 1,931 is the trapdoor.

What Makes RSA Difficult to Break?

The large number factorization... Continue reading "Understanding Cryptographic Functions and RSA Security" »

Sample Characteristics: Measures of Location and Variation

Measures of Location

• Average

  The average is a central value, often referred to as a measure of central tendency.

• Mean

  • Also known as the arithmetic mean.
  • Found by dividing the sum of all values by the total number of values.
  • Formula: Mean = (Sum of Quantities) / (Number of Quantities)
  • Example: Find the mean of 1, 2, 3, 4, 5, 6, 7, 8, 9, 10
    • Sum of values: 1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9 + 10 = 55
    • Number of values = 10
    • Mean of values = 55 / 10 = 5.5

• Median

  The median of a set is the middle number when the values are arranged in order from lowest to highest.

• Mode

  • The mode is the value that occurs most frequently in a set of values, also known as the modal value.
  • Example: Find the mode of 1, 2, 2, 3,

10 reasons to use games in language teaching

1.Games create a context for meaningful communication. 2. This meaningful communication serves as a basis for comprehensible input. 3. Games add interest to what learners find boring. 4. Games can be used with all language skills. 5. Games offer a fun experience. 6. Games encourage participation from all learners. 7. Games are learner-centered activities. 8. Games work outside of class. 9. Games promote cooperative learning. 10. Games fit into multiple intelligence theory.

Using Games in Teaching English to Young Learners: How to Choose a Game

Students may wish to play games purely for fun. Teachers need more convincing reasons. The key to a successful language game is that the rules are clear. The... Continue reading "Benefits of Using Games, Songs, and Stories in Language Teaching" »

Problem 4: Bank Savings Distribution

The average savings in the clients' accounts of a certain bank follow a normal distribution N(50,000, 15,000) (mean = 50,000 €, standard deviation = 15,000 €). The bank distributes its clients into three categories:

• Category A: Those clients that have less than 20,000 € in their savings account
• Category B: Those clients that have between 20,000 € and 80,000 € in their savings account
• Category C: Those clients that have more than 80,000 € in their savings account

Calculate:

4a) What percentage of clients belong to Category A?

Use the standard normal variable Z = (X - μ) / σ.

For X = 20,000 €:

Z = (20,000 - 50,000) / 15,000 = -30,000 / 15,000 = -2.000

The cumulative probability Φ(-2.00) ≈ 0.0228,... Continue reading "Normal Distribution Problems: Z‑Scores, Percentages & Parameters" »

Key Trends in Educational Outcomes (2009-2012)

• Equity in education outcomes deteriorated between 2009 and 2012.

Gender Differences in Academic Performance

• In 2012, girls outperformed boys in reading by an average of 29 score points.
• In 2012, boys outperformed girls by 16 score points in mathematics, a 7-point larger gender gap than seen in 2003.
• Across OECD countries, 42% of students (64% of girls) believe their failure in mathematics is due to a lack of ability. In Spain, this figure rises to 74% of students (80% of girls).

Socioeconomic Origin and Academic Performance

• In 2012, socioeconomically advantaged students outperformed less-advantaged students by 34 score points in mathematics.

Ethnicity and Academic Performance

• The immigrant student population

The Internet's Impact in the UK

Widespread Adoption and Recent History

The Internet has become an indispensable part of daily life in the UK, with widespread adoption across the population. It is now ubiquitous, found in homes, workplaces, and public spaces. Remarkably, just a decade ago, home Internet access was a rarity for many.

Demographics of UK Internet Users

In the UK, the largest percentage of Internet users falls within the 16-34 age bracket. As age increases, average Internet usage tends to decline, indicating a generational divide in digital engagement.

Popular Online Activities

Users frequently engage with various online platforms. The most commonly visited websites typically include social networking sites, email services, search engines,... Continue reading "Comprehensive Analysis: UK Digital Landscape & Car Performance" »

Programmer Position Application

Dear Mr. Gilhooley,

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The opportunity presented in this listing is very appealing to me, and I believe that my strong technical experience and education will make me a very competitive candidate for this position and an asset to your organization. The key strengths that I possess for success in this position include:

• I have been in charge of 23 people in private banking.
• I strive for continued excellence.
• I provide exceptional contributions to customer service for all customers.
• I am a conscientious person

6) Distribution channels for automobiles in Japan and the United States are similar in that most car buyers in both countries visit dealerships before making a purchase.

8) Kodak adopted a direct involvement approach in Japan by utilizing independent agents, distributors and retailers.

9) A distributor with good contacts is obviously the best one to select in terms of generating quick sales and revenues.

10) When utilizing the services of a local independent distributor, management is well advised to treat the distributor as a temporary market-entry vehicle.

11) An exporter that is new to a particular market would do well to choose a middleman with a reputation for "cherry picking" products.

12) When Carrefour, Tesco, or Walmart set up shop in developing... Continue reading "1" »

Operations Management Key Concepts

Inventory Management & Production Planning

• Final Inventories Analysis

  Final inventories for the last 4 months: FI = S(100) O(120) N(-130) D(430). Response: O(2750) N(1400) D(3750).

• Production Strategy Aggregation

  Which production strategy aggregates production? Response: Strategy to adjust demand.

• Production Planning Metrics

  Number of Products (N.Prod) = 10,000 units | Production Days = 20 | Workforce = 43. Response: 459 units.

• Actuation Possibilities

  Actuation possibilities: Demand/Capacity. Response: Actuation/Aggressive.

• Lot-for-Lot (LFL) Parameters

  LFL parameters: Ts2 Av25 Ss10 Level0 RefP3.

• Gross Requirements Calculation

  Gross Requirements: (0.50, 0.100, 0.75, 0.80, 0.90, 0.100). Response: (0.100, 0.70, 0.70,

Asset Accounting Fundamentals

Asset Acquisition

The acquisition cost of an asset includes all expenditures necessary to prepare the asset for its intended use.

1. Acquisition Cost Calculation:

   Purchase Price + All Expenditures Needed to Prepare the Asset (e.g., repair costs, real estate fees, title fees, installation costs, transportation costs).

   Does NOT include financing charges or cash discounts.

2. Acquisition by Construction:

   Costs include three main components:

   • All materials and labor
   • Factory overhead
   • Interest on debt incurred during construction

Capitalization, Depreciation, and Amortization

Capitalization involves recording an expense as an asset to spread its cost over its useful life.

Capitalization vs. Expensing

• Capitalization (Asset Account Debit