• The Korean Journal of Malacology
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• v.23 no.1
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• pp.31-38
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• 2007

Population ecological parameters and stock biomass of the purplish washington clam, Saxidomus purpuratus (Sowerby), in the southern coastal areas of Korea were determined based on the fishery data from the Divers Fisheries Cooperative and other available biological data. Instantaneous coefficient of total mortality (Z) of purplish Washington clam was estimated to be 0.7479/year. The estimated instantaneous coefficient of natural mortality (M) was 0.2012/year. From the values of Z and M, the instantaneous coefficient of fishing mortality coefficient (F) for the recent years was calculated to be 0.4578/year. The age of purplish Washington clam at its first capture ($t_c$) was 2.7506 year. Yield-per-recruit and spawning biomass-per-recruit were estimated under harvest strategies that bases on $F_{max}$, $F_{0.1}$, $F_{35%}$ and $F_{40%}$ were shown as 81.60 g, 61.68 g, 115.07 g and 131.51 g, respectively. The acceptable biological catch (ABC) was estimated to be about 1,404 metric tons.

• Health Policy and Management
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• v.28 no.1
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• pp.15-22
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• 2018

Background: Health is affected by various local factors. This study aims to investigate the age-standardized mortality variation of Seoul as well as the characteristics of the factors related to the mortality variation. Methods: The Korea Community Health Survey data, Seoul Survey data, Seoul statistics, and e-regional indicators of the National Statistical Office were used. To investigate the basic boroughs standardized mortality variation in Seoul, external quotient, coefficient of variation (CV), and systematic component of variation (SCV) values were suggested; correlation analysis and multiple regression analysis were conducted to investigate the characteristics related to standardized mortality rate. Results: The highest and the lowest standardized mortality rate of Seoul by boroughs had as much as 1.4 times difference; a low level of variation was shown in CV by 8.2; and was shown in SCV by 79. As a result of the multiple regression analysis of the factors that affect standardized mortality variation, the higher the rate of householders with college or higher, the lower the standardized mortality rate, and the higher the high-risk drinking rate, the higher the standardized mortality rate. Of the two, the rate of householder with a degree equivalent or higher than college was shown to have the biggest impact, followed by high-risk drinking rate. Conclusion: We found a variation in age-standardized mortality rate of boroughs in Seoul. The results suggest that policy makers should take into account socioeconomic environmental characteristics of community in developing community-based health promotion rather than focusing on lifestyle changes of residents.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.42 no.5
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• pp.487-493
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• 2009

Available ecological and fishery data of sailfin sandfish, Arctoscopus japonicus, was examined to ascertain its population dynamic parameters in Korean waters. The instantaneous coefficient of total mortality (Z) was estimated to be 1.361/yr, and annual survival rate (S) was 0.256. The estimated instantaneous coefficient of natural mortality (M) was 0.482/yr, and the instantaneous coefficient of fishing mortality (F) for recent years was calculated to be 0.879/yr from Z and M values. Age at first capture was estimated to be 1.958 years. These parameters, in conjunction with catch landings data between 1991 and 2008, were used to estimate annual biomass using a biomass-based cohort analysis. The biomass of A. japonicus was estimated at approximately 7,600 mt in 1991, but since 1994 decreased to below 4,000 mt by 2001. After 2002 they started to increase gradually, and showed the level of more than 5,000 mt in recent years.

• The Korean Journal of Health Service Management
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• v.9 no.2
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• pp.81-88
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• 2015

The purpose of this study was to compare the risk-adjusted in-hospital mortality for craniotomies between logistic regression and multilevel analysis. By using patient sample data from the Health Insurance Review & Assessment Service, in-patients with a craniotomy were selected as the survey target. The sample data were collected from a total number of 2,335 patients from 90 hospitals. The sample data were analyzed with SAS 9.3. From the results of the existing logistic regression analysis and multilevel analysis, the values from the multilevel analysis represented a better model than that of logistic regression. The intra-class correlation (ICC) was 18.0%. It was found that risk-adjusted in-hospital mortality for craniotomies may vary in every hospital. The agreement by kappa coefficient between the two methods was good for the risk-adjusted in-hospital mortality for craniotomies, but the factors influencing the outcome for that were different.

• Journal of Preventive Medicine and Public Health
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• v.45 no.1
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• pp.14-20
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• 2012

Objectives: The aim of this study was to evaluate and quantify the risk of both individual and combined health behaviors on premature mortality in middle aged men in Korea. Methods: In total, 14 533 male subjects 40 to 59 years of age were recruited. At enrollment, subjects completed a baseline questionnaire, which included information about socio-demographic factors, past medical history, and life style. During the follow-up period from 1993 to 2008, we identified 990 all-cause premature deaths using national death certificates. A Cox proportional hazard regression model was used to estimate the hazard ratio (HR) of each health risk behavior, which included smoking, drinking, physical inactivity, and lack of sleep hours. Using the Cox model, each health behavior was assigned a risk score proportional to its regression coefficient value. Health risk scores were calculated for each patient and the HR of all-cause premature mortality was calculated according to risk score. Results: Current smoking and drinking, high body mass index, less sleep hours, and less education were significantly associated with all-cause premature mortality, while regular exercise was associated with a reduced risk. When combined by health risk score, there was a strong trend for increased mortality risk with increased score (p-trend < 0.01). When compared with the 1-9 score group, HRs of the 10-19 and 20-28 score groups were 2.58 (95% confidence intervals [CIs], 2.19 to 3.03) and 7.09 (95% CIs, 5.21 to 9.66), respectively. Conclusions: Modifiable risk factors, such as smoking, drinking, and regular exercise, have considerable impact on premature mortality and should be assessed in combination.

• Fisheries and Aquatic Sciences
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• v.27 no.6
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• pp.392-409
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• 2024

The present study aims to analyze the biological aspects and population dynamics of Indian mackerel in Barru waters. Data was collected in Barru for 11 months, from June 2022 to April 2023. The observed parameters of biological aspects included gonadal maturation stages (GMSs), size at first gonadal maturation, and length-weight relationship. Meanwhile, the aspects of population dynamics encompass age group, growth, mortality rate, and exploitation rate. Data analysis consisted of morphological selection of general maturation stages, Spearman-Kärber method in estimating gonadal first maturation size, Bhattacharya method in identifying age group, von Bertalanffy function through FISAT II to measure growth (L_∞ and K), Pauly Model to estimate mortality rate, Beverton & Holt Model to estimate Y/R, and virtual population analysis (VPA) analysis to estimate stock and fish yield. The results demonstrated that GMS I was observed to be dominant, followed by stages II and III. The initial gonadal maturation was estimated to be 17.98-19.28 cm (FL) for females and 17.98-19.27 cm (FL) for males. The length-weight relationship in male and female Indian mackerels indicated a positive allometric growth. The mode grouping analysis results from the fork length measurement revealed three age groups. It was also identified that the asymptotic length (L_∞) = 29.5 cm (fork length), growth rate coefficient (K) = 0.46 per year, and theoretical age at zero length (t₀) = -0.3576 per year. Total mortality (Z) = 2.67 per year, natural mortality (M) = 1.10 per year, fishing mortality (F) = 1.57 per year, and exploitation rate (E) = 0.59, the actual Y/R = 0.083 gram/recruitment, and optimal Y/R 0.03 gram/recruitment. Fishing mortality is higher than the natural mortality rate, and a high exploitation value (E > 0.5) also reflects over-exploitation. VPA analysis on fish yields and stock estimation reported a highly exploited rate between the 11.5 cm and 14.5 cm length classes and an exceeding current yield of 467.07 tons/year with a recommended yield of 233.53 tons/year to ensure population sustainability.

• Journal of Trauma and Injury
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• v.32 no.1
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• pp.17-25
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• 2019

Purpose: We investigated how prehospital, emergency room (ER), and delta shock indices (SI) correlate with outcomes including mortality in patients with polytrauma. Methods: We retrospectively reviewed the medical records of 1,275 patients who visited the emergency department from January 2015 to April 2018. A total of 628 patients were enrolled in the study. Patients were divided into survivor and non-survivor groups, and logistic regression analysis was used to investigate independent risk factors for death. Pearson coefficient analysis and chi-square test were used to examine the significant relationship between SI and clinical progression markers. Results: Of 628 enrolled patients, 608 survived and 27 died. Multivariate logistic regression analysis reveals "age" (p<0.001; OR, 1.068), "pre-hospital SI >0.9" (p<0.001; OR, 11.629), and "delta SI ${\geq}0.3$" (p<0.001; OR, 12.869) as independent risk factors for mortality. Prehospital and ER SIs showed a significant correlation with hospital and intensive care unit length of stay and transfusion amount. Higher prehospital and ER SIs (>0.9) were associated with poor clinical progression. Conclusions: SI and delta SI are significant predictors of mortality in patients with polytrauma. Moreover, both prehospital and ER SIs can be used as predictive markers of clinical progression in these patients.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.46 no.5
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• pp.598-606
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• 2013

The blackfin flounder Glyptocephalus stelleri is a commercially important species in the East Sea of Korea, but its catches and biomass have decreased gradually in recent years. This study estimated the optimal catch (acceptable biological catch, ABC) for the effective management of this species by estimating population ecology parameters and the stock biomass of blackfin flounder in the East Sea of Korea. The estimated instantaneous coefficient of total mortality (Z) of blackfin flounder was 1.0542/year, the survival rate (S) was 0.3485, and the instantaneous coefficient of natural mortality (M) was 0.3637/year. From the values of S and M, the instantaneous coefficient of fishing mortality (F) was calculated to be 0.6905/year. The age at first capture was 1.304 years, and the total length was 11.5 cm at that time. On the basis of these parameters, the annual biomass was estimated by a biomass-based cohort analysis using annual catch data in weight by year for 1991-2012 in the East Sea of Korea. The annual biomass peaked in 1997 at about 12,800 mt and then subsequently declined continuously to a level of 10,500 mt in 2004 and to 9,800 mt in 2011 and 2012. The maximum sustainable yield and $F_{0.1}$ were estimated as 3,547 mt and 0.3595/year, respectively. Using these estimations, the ABC was estimated to be 3,571 mt in tier 5, 3,397 mt in tier 4, and 2,622 mt in tier 3.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.39 no.4
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• pp.344-348
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• 2006

The ecological characteristics and stock biomass of the Shiba shrimp, Metapenaeus joyneri, in Korean waters were determined, using fishery data from the Ministry of Maritime Affairs and Fisheries (MOMAF) and available length frequency data. The instantaneous coefficient of total mortality (Z) of M. joyneri was estimated to be 4.191year, and the annual survival rate (S) was 0.015. The estimated instantaneous coefficient of fishing mortality (F) for recent years was calculated to be 1.94/year. The age at first capture of M. joyneri was 0.71 years. Based on these parameters, the annual biomass of the M. joyneri stock was estimated using a biomass-based cohort analysis and data on the annual catch in weight at age for 1993-2004 in Korean waters. During the study period, the biomass of the shrimp peaked in 1994 at about 9,082 metric tons. Subsequently, it decreased to 500 metric tons in 1998.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.35 no.6
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• pp.686-695
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• 2002

Samples of Corbicula ( Corbicula) japonica Prime of Namdae Stream in Gangnung were collected from November 2000 to October 2001. Age of C. (C.) japonica was determined from the rings on the shell, The shell length of the samples ranged from 8 mm to 38 mm. The ring on the shell was formed once a year in March. Von Bertalanffy's growth parameters were estimated using a nonlinear regression method, asyinptotie shell length ($L_{\omega}$) was 48,98 mm, K was 0.20421year, theoretical age at 0 shell length $(t_0)$ was 0.3169 year, and asymptotic total weight ($W_{\omega}$) was 41.37 g. The formula of allomeky between shell length (L, mm) and total weight (W, g) of the brackish water clam was W=3.42$\times$10^{-4}L^{3}. The annual survival rate was estimated at 0.3799, instantaneous coefficient of natural mortality was 0.5007/year, and instantaneous coefficient of fishing mortality was 0.46721year. The age at first capture was estimated at 2.1593 year using shell length compositions of the brackish water clam, The current yield-per-recruit at 0.4672/year of fishing mortality was 0.6595 g. F_0.1 was estimated at 0.1865/year, Acceptable biological catch was estimated at 14.4 metric ton.