Question: However a log-periodic dipole array consists of a number of dipole elements of different lengths in order to obtain a somewhat directional antenna having an extremely wide bandwidth: these are frequently used for television reception in fringe areas. The dipole antennas composing it are all considered "active elements" since they are all electrically connected together (and to the transmission line). On the other hand, a superficially similar dipole array, the Yagi-Uda Antenna (or simply "Yagi"), has only one dipole element with an electrical connection; the other so-called parasitic elements interact with the electromagnetic field in order to realize a fairly directional antenna but one which is limited to a rather narrow bandwidth. The Yagi antenna has similar looking parasitic dipole elements but which act differently due to their somewhat different lengths. There may be a number of so-called "directors" in front of the active element in the direction of propagation, and usually a single (but possibly more) "reflector" on the opposite side of the active element.
Is there an answer to this question: What is the main application of these set ups?

Answer: television reception

Question: The reign of the Qianlong Emperor (17351796) saw the apogee and initial decline in prosperity and imperial control. The population rose to some 400 million, but taxes and government revenues were fixed at a low rate, virtually guaranteeing eventual fiscal crisis. Corruption set in, rebels tested government legitimacy, and ruling elites did not change their mindsets in the face of changes in the world system. Following the Opium War, European powers imposed unequal treaties, free trade, extraterritoriality and treaty ports under foreign control. The Taiping Rebellion (185064) and Dungan Revolt (186277) in Central Asia led to the deaths of some 20 million people. In spite of these disasters, in the Tongzhi Restoration of the 1860s, Han Chinese elites rallied to the defense of the Confucian order and the Qing rulers. The initial gains in the Self-Strengthening Movement were destroyed in the First Sino-Japanese War of 1895, in which the Qing lost its influence over Korea and the possession of Taiwan. New Armies were organized, but the ambitious Hundred Days' Reform of 1898 was turned back by Empress Dowager Cixi, a ruthless but capable leader. When, in response to the violently anti-foreign Yihetuan ("Boxers"), foreign powers invaded China, the Empress Dowager declared war on them, leading to defeat and the flight of the Imperial Court to Xi'an.
Is there an answer to this question: When was the first Sino-Japanese War?

Answer: 1895

Question: The devotio was the most extreme offering a Roman general could make, promising to offer his own life in battle along with the enemy as an offering to the underworld gods. Livy offers a detailed account of the devotio carried out by Decius Mus; family tradition maintained that his son and grandson, all bearing the same name, also devoted themselves. Before the battle, Decius is granted a prescient dream that reveals his fate. When he offers sacrifice, the victim's liver appears "damaged where it refers to his own fortunes". Otherwise, the haruspex tells him, the sacrifice is entirely acceptable to the gods. In a prayer recorded by Livy, Decius commits himself and the enemy to the dii Manes and Tellus, charges alone and headlong into the enemy ranks, and is killed; his action cleanses the sacrificial offering. Had he failed to die, his sacrificial offering would have been tainted and therefore void, with possibly disastrous consequences. The act of devotio is a link between military ethics and those of the Roman gladiator.
Is there an answer to this question: By dying what did Decius avoid for the battle?

Answer: disastrous consequences

Question: Besides the bit rate of an encoded piece of audio, the quality of MP3 files also depends on the quality of the encoder itself, and the difficulty of the signal being encoded. As the MP3 standard allows quite a bit of freedom with encoding algorithms, different encoders may feature quite different quality, even with identical bit rates. As an example, in a public listening test featuring two different MP3 encoders at about 128 kbit/s, one scored 3.66 on a 15 scale, while the other scored only 2.22.
Is there an answer to this question: The MP3 standard allows encoders to have a lot of freedom with which aspect of encoding?

Answer:
encoding algorithms