Detecting geo-relation phrases from web texts for triplet extraction of geographic knowledge: a context-enhanced method

Figures & data

Figure 1. Workflow of key-phrase detection for triplet extraction.

Table

The Park Güell is a public park system composed of gardens and architectonic elements located on Carmel Hill, in Barcelona, Catalonia (Spain).

Figure 2. Sparseness reduction for terms in contexts.

Figure 3. Example of categories regarding geo-entities in DBpedia ontology.

Table 1. Lexical features for term assessment.

#	Lexical feature
1	POS of term (noun, verb, preposition, or others)
2	location of term (left of e1, between e1 and e2, or right of e2)
3	previous term just before e1
4	next term just after e1
5	previous term just before e2
6	next term just after e2
7	distance between the term and e1
8	distance between the term and e2
9	distance between the term and the head of the sentence
10	distance between the term and the tail of the sentence

Table 2. Examples of detected key phrases of geo-entity pairs.

#	e1	e1	Terms in context	Key-phrase
1	Russian Empire	Asia	began, to, expand, into, from, 17th, century	expand
2	University of Alabama	Tuscaloosa	largest, single, campus, located, in, with, enrolled, fall	located
3	Afghan Defense University	Qargha	$200, million, under, construction, near, in	near
4	Albania	European Union	became, full, member, in, 2009, and, has, applied, to, join	join
5	Aberdeen Harbour	Scotland	important, largest, in, north, of, and, ferry, route, to, and	north
6	Broadway	Amsterdam Avenue	from, to, intersect, with, known, south, of	intersect
7	Teide	Spain	with, its, 3,718, metres, 12,198, feet, highest, peak, of, and, also, world, heritage, site	peak
8	Burley	Idaho	city, in, and, counties, in, southern, portion, of, state, of	southern
9	AAMI Park	Cox Architects	designed, by, with, input, from, Waratah, and, former, Wallaby, prop, Al, Baxter	designed
10	Oakham	Turners Hill	area, of, situated, on, peak, of, highest, point, in	situated
11	Astro Aruna	Astro Prima	replaced, by, from, 1, October, 2012, on, mio, TV, Channel, 602	replaced
12	Russian Empire	Asia	began, to, expand, into, from, 17th, century	expand

Figure 4. Example of the detected key phrases of geo-entity pair types.

Figure 5. Cumulative frequency of the key phrase (property) number of each geo-entity pair type.

Table 3. Statistics of key-phrase detections.

Method	#Extracted geo-entity pair type	#Detected key phrases
DF	1,896	12,753
Entropy	1,709	8,626
Proposed	1,784	10,031

Table 4. Precision of key-phrase detection.

Method	Cnt(right set)	Precision(%)
DF	509	50.90%
Entropy	545	54.50%
Proposed	727	72.70%

Data availability statement

The data referred to in this paper is not publicly available at the current time.