D684 Introduction to Computer Science - Set 2 - Part 3

Correct Answer: Hash function

Hash functions generate unique fingerprints from documents, enabling detection of any modifications by comparing hash values.
Option a is incorrect because symmetric keys encrypt and decrypt but don't specifically detect document modifications after signing.
Option c is incorrect because random numbers provide unpredictability for security but don't verify document integrity or authenticity.
Option d is incorrect because timestamps record signing time but don't detect whether document content was modified after signing.

Correct Answer: Optimistic synchronization

Optimistic synchronization assumes operations succeed then corrects conflicts later, maintaining smooth gameplay despite latency variations between players.
Option b is incorrect because pessimistic locking blocks operations until confirmed, causing gameplay stuttering with high latency connections.
Option c is incorrect because eventual consistency allows temporary inconsistencies that could unfairly advantage some players over others.
Option d is incorrect because strict ordering waits for all events in sequence, making games unplayable with high latency differences.

Correct Answer: Dead code elimination

Dead code elimination identifies and removes code sections that program flow can never reach, reducing executable size and complexity.
Option a is incorrect because loop unrolling expands loops to reduce iteration overhead, not removing unreachable code sections.
Option c is incorrect because constant folding evaluates constant expressions at compile time, not removing unreachable code blocks.
Option d is incorrect because register allocation assigns variables to processor registers for speed, unrelated to removing unreachable code.

Correct Answer: Edge computing

Edge computing places computational resources and data near users geographically, reducing latency by serving content from nearby locations.
Option a is incorrect because port forwarding redirects network traffic to specific ports but doesn't consider geographic proximity to users.
Option c is incorrect because tunneling creates secure connections through networks but doesn't optimize for geographic content distribution.
Option d is incorrect because broadcasting sends data to all network nodes simultaneously, inefficient for targeted geographic content delivery.

Correct Answer: Real-time kernel

Real-time kernels guarantee deterministic timing for critical operations, essential for precise sensor-motor coordination in robotics systems.
Option a is incorrect because monolithic kernels optimize for throughput and features but don't guarantee timing precision for robotics.
Option b is incorrect because microkernels minimize kernel size for reliability but don't specifically provide real-time timing guarantees.
Option d is incorrect because hybrid kernels balance performance and modularity but lack the timing guarantees robotics control requires.

Correct Answer: Sandboxing

Sandboxing restricts JavaScript execution within controlled environments, preventing malicious code from accessing system resources or user data.
Option a is incorrect because process isolation separates processes but JavaScript typically runs within the browser process requiring finer control.
Option c is incorrect because virtualization creates entire virtual machines, too heavyweight for isolating individual web page scripts.
Option d is incorrect because containerization packages applications with dependencies, not designed for isolating untrusted script execution.

Correct Answer: Blockchain ledger

Blockchain ledgers create immutable records of product journey, making counterfeit insertion detectable through cryptographic verification of history.
Option a is incorrect because relational databases can be modified retroactively, allowing potential counterfeit record insertion without detection.
Option c is incorrect because file systems store data but don't provide immutable audit trails required for authenticity verification.
Option d is incorrect because message queues transfer data between systems but don't maintain permanent traceable product histories.

Correct Answer: Closed-loop control

Closed-loop control continuously adjusts based on feedback from sensors about wind and obstacles, maintaining stable autonomous flight.
Option a is incorrect because open-loop control doesn't use feedback to adjust for changing wind conditions or unexpected obstacles.
Option c is incorrect because manual control requires human operators, defeating the purpose of autonomous drone flight operation.
Option d is incorrect because batch control processes at intervals, too slow for continuous flight path adjustments during operation.

Correct Answer: Stress testing

Stress testing pushes systems beyond normal capacity to identify breaking points and behavior under extreme load conditions.
Option a is incorrect because unit testing verifies individual components in isolation, not system behavior under extreme load conditions.
Option b is incorrect because integration testing checks component interactions but doesn't test system limits under extreme loads.
Option d is incorrect because regression testing ensures changes don't break existing functionality, not testing extreme load conditions.

Correct Answer: Superposition

Superposition allows quantum states to exist in multiple states simultaneously until measurement collapses them to definite values.
Option a is incorrect because determinism implies predictable single states, opposite of quantum simultaneous multiple state existence.
Option c is incorrect because recursion involves functions calling themselves, not related to simultaneous multiple state existence.
Option d is incorrect because inheritance is object-oriented programming concept for deriving properties, not quantum state behavior.