The systematic sampling for inferring the survey indices of Korean groundfish stocks

Table 2 Inference of the relative sizes (in thousands) of 11 stocks in 2014

Season	Stock	\( \widehat{Y_s} \)	\( \widehat{SE}{\left(\widehat{Y_s}\right)}_{SRS} \)	\( \widehat{SE}{\left(\widehat{Y_s}\right)}_{SYS} \)	Change (%)
Spring	1	27.0	11.1	8.5	− 24.08
	2	2696.3	1569.4	1303.5	− 16.95
	3	549.3	528.4	536.4	1.50
	4	17.2	8.5	8.5	− 0.03
	5	52.6	26.2	26.1	− 0.39
	6	469.5	187.8	180.4	− 3.91
	7	10.4	4.4	4.0	− 8.33
	8	8.3	3.2	2.9	− 8.45
	9	20.8	7.4	7.3	− 0.98
	10	28.8	10.8	7.7	− 28.76
	11	269.3	90.0	87.7	− 2.57
Fall	1	161.3	85.3	62.5	− 26.70
	2	1107.6	507.4	468.2	− 7.72
	3	9171.1	7555.7	7692.5	1.81
	4	28.9	21.3	21.1	− 0.85
	5	6.5	3.2	2.9	− 6.66
	6	664.1	234.5	224.0	− 4.48
	7	66.2	18.9	16.2	− 14.61
	8	8.5	5.0	5.0	− 0.53
	9	110.9	27.1	22.2	− 18.01
	10	1.5	0.8	0.7	− 2.61
	11	2463.1	1109.1	957.9	− 13.63

The column of “Change (%)” indicates a change in the standard error (SE) under the systematic sampling (SYS) relative to that under the simple random sampling (SRS), i.e., Change (%) = \( 100\cdot \left[\left(\widehat{SE}{\left({\widehat{Y}}_s\right)}_{SYS}-\widehat{SE}{\left({\widehat{Y}}_s\right)}_{SRS}\right)/\widehat{SE}{\left({\widehat{Y}}_s\right)}_{SRS}\right] \). Those 11 stocks are as follows: 1 = Pacific cod (Gadus macrocephalus); 2 = White croaker/Silver jewfish (Argyrosomus argentatus); 3 = Pacific herring (Clupea pallasii); 4 = Red tilefish (Branchiostegus japonicus); 5 = Blackfin flounder (Glyptocephalus stelleri); 6 = Yellow croaker (Larimichthys polyactis); 7 = Gazami crab (Portunus trituberculatus); 8 = Mottled skate (Raja pulchra); 9 = Chub mackerel (Scomber japonicus); 10 = Black scraper (Thamnaconus modestus); 11 = Largehead hairtail (Trichiurus lepturus)

ISSN: 2234-1757