Table 5. The frequency and definition of keywords in urban regeneration

Period	1920∼1945		1946∼1959		1960∼1969		1970∼1979		1980∼1989		1990∼1999
Definition	Japanese colonial rule and liberation		Korean War and restoration		Industrialization and development centuries		The birth of environmental awareness		A shift in environmental awareness		Environmental and ecological practice
Ranking	Keywords	Fre.	Keywords	Fre.	Keywords	Fre.	Keywords	Fre.	Keywords	Fre.	Keywords	Fre.
1	Rural	54	Republic of Korea	51	Foreign country	155	Urban	195	Urban	155	Urban	260
2	Urban	46	Problem	42	Culture	118	Foreign country	143	Environmental pollution	130	Regeneration	178
3	Joseon	34	Production	34	Urban	107	Garbages	126	Environmental	121	Foreign country	91
4	Economy	33	Farmer	27	Art	99	Waste	121	Regeneration	107	Development	66
5	Countries in Europe and America	31	Freedom	26	Rural	95	Green space	116	Culture	105	Garbages	65
6	Advancement	26	Rural	26	Green space	94	Regeneration	111	Garbages	88	Waste product	61
7	Agriculture	25	Country	26	Economy	94	Problem	89	Development	58	Environmental	57
8	Life	23	Rice	25	Our country	85	Pollution	88	Foreign country	56	Seoul	46
9	Economic collapse	23	Next	25	Social issue	77	Culture	86	Waste	45	Recycling	43
10	Disaster	21	Government	24	Leisure	73	Human	76	Metropolitan area	44	Disposal	37
11	Health	19	Urban	23	Agriculture	71	Development	72	Local	34	Green space	35
12	Problem of drinking water	18	Land	21	Reality	58	Population	70	Disposal	33	Technology	35
13	Countermeasure	18	Funding	21	People	49	Contamination	67	Alternative energy	29	Environmental pollution	34
14	Campaign	17	Nationality	21	Development	48	Seoul	62	Green space	29	Ministry of Environment	31
15	Society	17	Economic	21	Farmer	44	Economy	61	Environmental Office	28	Local	31
16	Farmer	17	Nation	20	Policy	34	Environmental	54	City traffic	28	Culture	31
17	Problem	16	Ceasefire	19	Industry	34	Resources	54	Factory	28	Separate collection	27
18	Confront	15	Need	18	Society	34	Disposal	53	Damage	26	Construct	27
19	Industry	14	Lancashire	18	Regeneration	31	Agriculture	49	Territory	26	Space	26
20	Regeneration	13	Action	17	Land	29	Life	48	Government	22	Nature	25
21	General	13	Reconstruction	17	Emotion	28	Rural	47	Rural	22	Business	24
22	Solidarity	13	Capital	17	Roof improvement project	26	Government	42	Human	21	Possibility	24
23	Phenomenon	12	Industry	17	Method	26	Plan	42	Life	21	Korea	23
24	Province	12	Conference	16	Problem	26	Production	40	Use	20	Energy	23
25	Culture	12	Disposal	16	International	26	Industry	38	Problem	20	Facility	23
26	Value	12	Agriculture	16	Preservation	24	Technology	38	Plan	19	Construction	23
27	Simultaneity	11	Relation	16	Advancement	23	Local	36	Resources	18	Industry	22
28	Financial	11	Investment	15	Plan	22	Factory	36	Business	18	Factory	21
29	Educational establishment	11	Simultaneity	15	Increase	21	Administration	34	Survey	17	Rural	20
30	Cooperation company	10	Over	14	Population	21	Metropolitan	34	Industry	17	Incineration	19