D686 Operating Systems for Computer Scientists - Set 5 - Part 3

Correct Answer: Proportional sharing

Proportional sharing allocates rewards based on computational contribution percentage, ensuring miners receive fair compensation relative to their processing power invested in pool mining operations collectively conducted continuously throughout.
Option a is incorrect because equal distribution ignores contribution differences unfairly rewarding minimal contributors; mining pools need proportional not uniform rewards for fairness among participants contributing differently significantly.
Option c is incorrect because random rewards disconnect effort from compensation destroying incentives; mining needs merit-based not arbitrary rewards for sustainable pool participation maintained over time consistently required.
Option d is incorrect because winner-takes-all discourages small miners from participating; pools need shared not individual rewards for collective mining viability and decentralization benefits achieved practically effectively.

Correct Answer: Continuous replication

Continuous replication maintains real-time synchronization between sites, enabling instant failover without data loss when disasters strike primary facilities, ensuring business continuity through seamless transition capability maintained constantly.
Option a is incorrect because periodic backups have gaps causing data loss between backups; disaster recovery needs continuous not intermittent replication for zero data loss objectives required critically.
Option c is incorrect because manual copying is too slow and error-prone for disaster recovery; critical systems need automated not human replication for reliability and speed required operationally.
Option d is incorrect because scheduled sync leaves windows of potential data loss; business continuity needs real-time not scheduled replication for complete protection against disasters occurring unexpectedly suddenly.

Correct Answer: Precision timing distribution

Precision timing distribution delivers synchronized triggers to all magnets within nanoseconds, essential for controlling particle beams traveling near light speed through accelerator rings requiring exact coordination throughout continuously.
Option a is incorrect because local timing causes phase drift destroying beam focus; particle accelerators need global not independent timing for beam control precision required fundamentally for experiments conducted.
Option c is incorrect because approximate sync causes beam instability and particle loss; accelerators need precise not rough synchronization for experimental validity and safety absolutely required necessarily mandated.
Option d is incorrect because manual coordination is impossibly slow for nanosecond precision; particle physics needs automated not human timing for beam control at relativistic speeds required operationally.

Correct Answer: Electronic surveillance

Electronic surveillance continuously monitors RFID tags detecting unpurchased items near exits, providing automatic theft prevention without requiring individual item inspection by security personnel throughout store operations continuously conducted.
Option a is incorrect because manual checking is slow creating queues and missing concealed items; retail security needs automated not human detection for effective loss prevention practically achievable.
Option c is incorrect because random inspection misses most theft attempts between checks; stores need continuous not sporadic monitoring for effective theft deterrence and detection consistently required operationally.
Option d is incorrect because honor system provides no theft prevention relying on customer honesty; retail requires active not passive security for loss prevention absolutely necessary for profitability.

Correct Answer: Solar tracking

Solar tracking systems calculate sun position adjusting panels for optimal angle continuously, increasing energy generation significantly compared to fixed installations by maintaining perpendicular alignment throughout daylight hours necessarily.
Option a is incorrect because fixed positions miss optimal angles most of the day; solar farms need dynamic not static positioning for maximum energy harvest throughout sunlight hours available.
Option c is incorrect because random movement would reduce not increase energy capture; solar panels need calculated not arbitrary positioning for optimal sun exposure continuously maintained throughout operation.
Option d is incorrect because manual adjustment is impractical for large installations; solar farms need automated not human panel control for efficient operation at scale required commercially.

Correct Answer: Liveness detection

Liveness detection analyzes micro-movements, blood flow, and depth information confirming living persons not replicas, preventing fraud through sophisticated biometric spoofing attempts using photographs or three-dimensional masks potentially presented.
Option a is incorrect because static scanning can't distinguish photos from real faces; payment security needs dynamic not static verification for fraud prevention absolutely required for financial systems.
Option c is incorrect because simple matching accepts any matching pattern including fakes; secure payments need liveness not just similarity verification for fraud prevention essentially required operationally necessarily.
Option d is incorrect because visual checks by humans are subjective and slow; automated liveness detection provides objective rapid verification for payment system efficiency and security required.

Correct Answer: Domain decomposition

Domain decomposition splits atmosphere into regions processed simultaneously on different nodes, enabling weather prediction at resolutions impossible with sequential processing through massive parallelization across supercomputing clusters available currently operationally.
Option a is incorrect because sequential processing is too slow for timely weather forecasts; meteorology needs parallel not serial computation for practical prediction timescales required for public warnings.
Option c is incorrect because random distribution creates communication overhead and load imbalance; weather modeling needs systematic not arbitrary decomposition for computational efficiency maximized throughout simulations running continuously.
Option d is incorrect because single calculations can't handle global atmospheric complexity; weather prediction needs distributed not centralized processing for resolution and speed required practically for forecasting.

Correct Answer: Real-time synchronization

Real-time synchronization continuously updates digital twins with sensor data from physical systems, enabling accurate simulation and prediction of maintenance needs before failures occur potentially preventing downtime effectively.
Option a is incorrect because manual updates create dangerous gaps between model and reality; digital twins need automatic not human synchronization for accurate representation continuously maintained throughout operation necessarily.
Option c is incorrect because periodic refresh leaves models outdated between updates; predictive maintenance needs continuous not intermittent synchronization for timely failure prediction required operationally for reliability assurance.
Option d is incorrect because static models don't reflect system changes over time; digital twins need dynamic not fixed modeling for maintenance prediction accuracy throughout equipment lifecycle necessarily required.

Correct Answer: Neural decoding

Neural decoding algorithms filter noise and extract intention patterns from complex brain signals, translating thoughts into prosthetic control commands enabling paralyzed patients to control artificial limbs naturally.
Option a is incorrect because raw signals contain too much noise for direct control; brain interfaces need processed not unfiltered signals for reliable prosthetic control practically achievable medically required.
Option c is incorrect because random interpretation produces unpredictable dangerous movements; prosthetics need deterministic not arbitrary decoding for safe patient control absolutely required for medical devices fundamentally.
Option d is incorrect because simple thresholds miss complex intention patterns in neural activity; advanced prosthetics need sophisticated not basic signal processing for natural control interfaces required therapeutically.

Correct Answer: Parallel recognition

Parallel recognition distributes video analysis across multiple processors simultaneously checking all feeds, enabling real-time identification of persons of interest among thousands of attendees entering venues continuously throughout events.
Option a is incorrect because sequential scanning is too slow for real-time crowds; stadium security needs parallel not serial processing for timely threat detection during entry periods critically required.
Option c is incorrect because manual review can't process thousands of faces quickly enough; venue security needs automated not human recognition for practical crowd screening capabilities required operationally necessarily.
Option d is incorrect because random checking misses potential threats between samples; security requires comprehensive not probabilistic screening for public safety assurance at large gatherings absolutely mandated legally.