Notes, summaries, assignments, exams, and problems for Secondary education

Chapter 5: Synchronization

Critical Section Conditions

• Mutual Exclusion: Only one process may be in the critical section at a time.
• Progress: If the critical section is empty, some waiting process can enter.
• Bounded Waiting: No starvation; each process waits a bounded number of turns.

Atomic Instructions

• Test-and-Set: old = *b; *b = TRUE; return old
• Swap: temp = *a; *a = *b; *b = temp

Spinlocks

• TAS:

  bool m = false;
  lock() { while (TestAndSet(&m)); }
  unlock() { m = false; }
  

• Swap:

  bool m = false;
  lock() { bool key = true; while (key) Swap(&m, &key); }
  unlock() { m = false; }
  

Semaphores

• wait(S): S.val--; if S.val < 0 block
• signal(S): S.val++; if S.val <= 0 wake one
• Binary semaphore as mutex: init = 1; lock = wait; unlock = signal

Peterson's

Chemistry Fundamentals and Reactions

Chemical Bonding Types

• Ionic Bonding: Metal + Non-metal → Electrons are transferred.
• Covalent Bonding: Non-metal + Non-metal → Electrons are shared.

Chemical Naming Conventions

• Ionic Naming: Metal + Non-metal (ending in “-ide”). Use Roman numerals for multivalent metals. Includes polyatomic ions.
• Molecular Compounds: Use prefixes (mono-, di-, tri-, etc.).
• Diatomic Elements: H₂, O₂, F₂, Br₂, I₂, N₂, Cl₂.

Properties of Compounds

• Ionic Compounds: Solid state, high melting/boiling points, conducts electricity when dissolved (aqueous).
• Molecular Compounds: Low melting/boiling points, poor electrical conductors.

Balancing Chemical Equations

The process follows the Law of Conservation of Mass:

1. Word Equation
2. Skeleton

The History of Al-Andalus (711–1492)

Al-Andalus was the Muslim state established in the Iberian Peninsula in the 8th century. Its borders and government changed significantly over the centuries, primarily due to internal disputes between different groups.

The Conquest of the Iberian Peninsula (711–718)

In 711, a small Muslim group led by Tariq crossed the Strait of Gibraltar and defeated the Visigoths at the Battle of Guadalete. The Visigothic Kingdom was suffering an economic crisis, which facilitated the advance of subsequent Muslim armies. By 722, they controlled almost all the peninsula except a narrow strip in the north where the Hispano-Visigoths took refuge.

After conquering Hispania, the Umayyad Caliph of Damascus established the Emirate... Continue reading "Al-Andalus: Islamic Rule and Medieval Iberian Kingdoms" »

English Grammar Practice: Sentence Construction & Verb Usage

Choose the Correct Option: Quantifiers & General Usage

• I had many interesting experiences during that year.
• My dad has a lot of work.
• There isn’t enough space in this.
• I’ve been to this train station many times.
• There is a lot of competition between big supermarkets.

Complete the Sentences: Quantifiers & Context

• There is a flea market every Sunday.
• All my friends enjoy it.
• Many people drive, but few cycle.
• I’d rather travel on the train; there’s little choice and it's efficient.
• This is a pedestrian zone; no motor vehicles are allowed.
• I’ve been to Paris several times.
• There wasn’t much traffic.
• There is plenty to see.

Modal Verbs: Choose the Correct Option

• The lecturer must

Character & Conflict Analysis

Robinchon's Defeat by Marquis de Theremin

Question: How was Robinchon defeated by Marquis de Theremin? (4 marks)

Answer: Robinchon was defeated by the Marquis through a clever trick. The Marquis used his intelligence and experience to outwit Robinchon, exposing his lack of real knowledge and making him appear foolish in front of others. This resulted in Robinchon losing both credibility and respect.

Robinchon's Lecture at Apperville sous Bois

Question: What was the effect of Robinchon’s lecture at Apperville sous Bois? (2 marks)

Answer: Robinchon’s lecture left the audience unimpressed, leading to his humiliation.

Themes of Love & Sacrifice

Jim and Della: A Comparison to the Magi

Question: Why were Jim and Della... Continue reading "Literary & Historical Insights: Key Questions & Interpretations" »

Number and Quantity Prefixes

• Mono-, Uni- (one):
  • Monodiplopia: Double vision that occurs only in one eye.
  • Unilateral: Confined to one side only.
• Bi-, Di- (two, twice, double):
  • Diplopia: Double vision.
  • Bilateral: Affecting two sides.
• Tri- (three):
  • Trigeminal nerve: The fifth cranial nerve, providing sensory innervation to the face, divided into three main branches.
• Quad-, Quadra-, Tetra- (four):
  • Quadrant: Areas divided for descriptive purposes into quadrants.
  • Tetradactyl: Having four fingers or toes on a hand or foot.
• Multi- (many):
  • Multicellular: Composed of many cells.
• Poly- (too much, many):
  • Polyuria: Excessive excretion of urine.
• Hemi-, Semi- (half or partly):
  • Hemiplegia: Paralysis of one side of the body.
  • Semicomatose: State of drowsiness and inaction, requiring

The Rise of Feudalism (10th Century)

In the 10th century, feudalism emerged as the new way of structuring and governing society. This system was based on relationships of mutual dependence between social groups, involving rights and duties on both sides. It primarily involved two main relationships: vassalage and servitude.

The Weakening of Monarchs and the Birth of Vassalage

Between the 9th and 10th centuries, the Carolingian Empire was divided into kingdoms. This division weakened the monarchs, who frequently clashed. This unstable situation, coupled with invasions, fragmented Europe. Monarchs struggled to manage this insecurity; they lacked the means to collect taxes or maintain an army sufficient to protect the populace.

To govern and defend... Continue reading "Medieval Power Dynamics: Feudal Society and the Role of the Church" »

Riba's Contribution to Poverty

Riba (usury) exacerbates poverty by exploiting people's wealth. It is a significant factor in rising prices and economic recession. Furthermore, it diminishes charitable acts and cooperation within society. From a moral standpoint, it strips human actions of their blessings. Borrowers often struggle to repay loans, ultimately leading to increased interest and indebtedness.

Risks of Accusing Chaste Women of Adultery

Accusing a chaste woman of adultery is an extremely serious offense and constitutes slander. Such accusations jeopardize her reputation and honor, leading to defamation within the community. They can also severely damage families, promote immorality, and foster animosity among people.

Benefits of Zakat

Exercise 1: Vocabulary Identification

• Issues
• Overpopulation
• Moreover
• Homelessness
• Famine
• Cheated
• Expelled
• Fell
• Subjects
• Sororities
• Diet
• Publicity
• Unfit
• Get involved
• Lose
• Creative
• Passionate
• Irresponsible
• Importance
• Tolerant

Exercise 2: Vocabulary Matching and Definitions

• Nation: national, country
• Folklore: culture
• Reception: host
• Color of skin: race
• Country of origin: nationality
• The condition of being a woman or a man: gender
• 8. Immigrants
• Armed conflicts: wars
• Illnesses: diseases
• Extreme weather conditions: climate change
• Displaced people: refugees
• Really cheap: bargain
• Reduction: discount
• Used: second-hand
• Wait in line:
• Coins and notes: cash
• Plastic money: a credit card
• Ask for money from a friend: borrow
• To give money on the condition of repayment: lend

Exercise 3: Verb Tenses

Franco's Spain was characterized by a personal dictatorship, militarism, Catholicism, and Spanish unitary nationalism. It operated as a single-party state, with the Spanish Falange suppressing political opposition and trade unions. The country experienced a permanent division between the victors and the vanquished.

Social support for the regime came from the army, the church, the Falange, traditionalists, landowners, financiers, business owners, small and medium agricultural owners, and the middle class.

The totalitarian stage saw the establishment of a new political regime without a constitution or democratic freedoms, concentrating all power in Franco. Institutions from the Republican era were dismantled, including the 1931 Constitution with... Continue reading "Franco's Spain: Dictatorship to Economic Liberalization" »