Problem: Data compression:

Today, nearly all commonly used video compression methods (e.g., those in standards approved by the ITU-T or ISO) apply a discrete cosine transform (DCT) for spatial redundancy reduction. The DCT that is widely used in this regard was introduced by N. Ahmed, T. Natarajan and K. R. Rao in 1974. Other methods, such as fractal compression, matching pursuit and the use of a discrete wavelet transform (DWT) have been the subject of some research, but are typically not used in practical products (except for the use of wavelet coding as still-image coders without motion compensation). Interest in fractal compression seems to be waning, due to recent theoretical analysis showing a comparative lack of effectiveness of such methods.

Who introduced redundancy reduction in 1974?
---
A: unanswerable


Problem: In the late 1980s, many local Chicago house music artists suddenly found themselves presented with major label deals. House music proved to be a commercially successful genre and a more mainstream pop-based variation grew increasingly popular. Artists and groups such as Madonna, Janet Jackson, Paula Abdul, Aretha Franklin, Bananarama, Diana Ross, Tina Turner, Whitney Houston, Steps, Kylie Minogue, Bjork, and C+C Music Factoryhave all incorporated the genre into some of their work. After enjoying significant success in the early to mid-90s, house music grew even larger during the second wave of progressive house (1999–2001). The genre has remained popular and fused into other popular subgenres, for example, G-house, Deep House, Tech House and Bass House. As of 2015, house music remains extremely popular in both clubs and in the mainstream pop scene while retaining a foothold on underground scenes across the globe.[citation needed]
where is house music extremely popular?
---
Answer: both clubs and in the mainstream pop scene


Q: What is a question about this article? If the question is unanswerable, say "unanswerable".
When an inductive circuit is opened, the current through the inductance collapses quickly, creating a large voltage across the open circuit of the switch or relay. If the inductance is large enough, the energy will generate a spark, causing the contact points to oxidize, deteriorate, or sometimes weld together, or destroying a solid-state switch. A snubber capacitor across the newly opened circuit creates a path for this impulse to bypass the contact points, thereby preserving their life; these were commonly found in contact breaker ignition systems, for instance. Similarly, in smaller scale circuits, the spark may not be enough to damage the switch but will still radiate undesirable radio frequency interference (RFI), which a filter capacitor absorbs. Snubber capacitors are usually employed with a low-value resistor in series, to dissipate energy and minimize RFI. Such resistor-capacitor combinations are available in a single package.
What type of capacitor is used to make a path to not bypass the contact points?
A: unanswerable


Context and question: Beginning in February 1988, the Democratic Movement of Moldova (formerly Moldavia) organized public meetings, demonstrations, and song festivals, which gradually grew in size and intensity. In the streets, the center of public manifestations was the Stephen the Great Monument in Chişinău, and the adjacent park harboring Aleea Clasicilor (The "Alee of the Classics [of the Literature]"). On January 15, 1988, in a tribute to Mihai Eminescu at his bust on the Aleea Clasicilor, Anatol Şalaru submitted a proposal to continue the meetings. In the public discourse, the movement called for national awakening, freedom of speech, revival of Moldavian traditions, and for attainment of official status for the Romanian language and return to the Latin alphabet. The transition from "movement" (an informal association) to "front" (a formal association) was seen as a natural "upgrade" once a movement gained momentum with the public, and the Soviet authorities no longer dared to crack down on it.
What was Moldova's previous name?
Answer: Moldavia


Question: In Argentina, the most representative Carnival performed is the so-called Murga, although other famous Carnivals, more like Brazil's, are held in Argentine Mesopotamia and the North-East. Gualeguaychú in the east of Entre Ríos province is the most important Carnival city and has one of the largest parades. It adopts a musical background similar to Brazilian or Uruguayan Carnival. Corrientes is another city with a Carnival tradition. Chamame is a popular musical style. In all major cities and many towns throughout the country, Carnival is celebrated.
Is there an answer to this question: Which Carnival in Argentina is the most representative of the nature of the Carnival?

Answer: Murga


Q: What is a question about this article? If the question is unanswerable, say "unanswerable".
The city management and urban policy program was ranked first in the nation, and the special education program second, by U.S. News & World Report's 2016 rankings. USN&WR also ranked several programs in the top 25 among U.S. universities.
In what tier did a number of KU's programs rank in 2016?
A:
the top 25