Analysis on Port and Maritime Transport System Researches

Table 12

Ranking dynamics of research terms.

	Word	TF-IDF	Word	TF-IDF		Word	TF-IDF		Word	TF-IDF
		(1996-2000)		(2001-2005)			(2006-2010)			(2011-2015)
1	freight	2.88	container	3.46	▲	port	16.37	▲	port	20.67	-
2	network	2.34	port	3.24	▲	container	14.64	▼	container	18.52	-
3	science	2.11	yard	2.45	-	shipping	8.27	▲	shipping	14.50	-
4	container	2.09	cost	2.28	▲	terminal	8.07	▲	ship	13.86	▲
5	carrier	2.00	truck	2.19	▲	cost	7.86	▼	emission	12.10	-
6	intermodal	1.99	heuristic	1.98	-	maritime	7.45	-	terminal	11.02	▼
7	transportation	1.83	ship	1.90	▲	transport	7.42	▲	cost	9.75	▼
8	risk	1.82	terminal	1.86	▲	market	7.09	▲	network	9.46	▲
9	port	1.76	vehicle	1.76	-	crane	6.94	▲	transport	9.29	▼
10	policy	1.65	safety	1.76	▲	transportation	6.85	▲	service	8.69	▲
11	terminal	1.56	policy	1.73	▼	yard	6.27	▼	freight	8.48	▼
12	truck	1.56	transport	1.71	▲	berth	6.17	-	control	8.47	-
13	ocean	1.54	crane	1.67	-	scheduling	5.97	-	algorithm	8.43	▲
14	service	1.51	transportation	1.65	▼	ship	5.94	▲	approach	8.16	▲
15	market	1.50	algorithm	1.62	-	network	5.87	▼	liner	7.93	-
16	operation	1.49	capacity	1.61	-	operation	5.79	-	crane	7.91	▼
17	ship	1.45	market	1.57	▼	service	5.61	▲	maritime	7.73	▼
18	transport	1.44	shipping	1.48	-	approach	5.43	-	risk	7.66	▼
19	cost	1.41	service	1.48	▼	vessel	5.36	-	optimal	7.61	-
20	safety	1.31	product	1.44	-	algorithm	5.34	-	cargo	7.48	-