• Fisheries and Aquatic Sciences
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• v.27 no.8
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• pp.515-524
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• 2024

The high economic value and demand for shark fin have significantly increased the vulnerability of the shortfin mako shark (Isurus oxyrinchus Rafinesque, 1810) population in the Indian Ocean, particularly in the southern region of Java and West Nusa Tenggara. This study utilized a length-based assessment method to evaluate the stock status of I. oxyrinchus. Over a span of eight years (2013-2021), data on length frequency and sex composition were collected. The length-based spawning potential ratio (SPR) was employed to investigate the stock status of the fishery. The findings revealed that I. oxyrinchus exhibited a large body size, with an asymptotic length estimated at 386.86 cm total length and a growth coefficient of 0.04/year . Females were more frequently captured than males, and evidence indicated a declining trend in the size of female sharks. A low SPR value of approximately 6% indicated the overfishing condition of mako shark. To ensure the sustainability of the shortfin mako shark population in the Indian Ocean, it is essential to develop effective management strategies through integrated cooperation among the government, fishers, traders, shark industries, and local communities.

• Korean Journal of Environment and Ecology
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• v.34 no.1
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• pp.9-17
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• 2020

Domestic cats (Felis catus) introduced to insular environments can be invasive predators that often threaten endemic species and cause biodiversity loss or local extinction on the island. This study was conducted from March to July 2018 to understand the population size, home range, and spatial use of cats introduced to Mara Islet (N 33° 07', E 126° 16') in Jeju Special Governing Province, the Republic of Korea. Observation records based on their natural marks revealed that there were 20 adult cats on Mara Islet. A capture-recapture method also estimated 20 adult individuals (95% confidence interval: 20-24 individuals). According to our telemetry study on ten adults deployed with GPS-based telemetry units, the home range size was 12.05±6.99 ha (95% KDE: kernel density estimation), and the core habitat size was 1.60±0.77 ha (50% KDE). There were no significant differences in the home range and core habitat sizes by sex. The home range of domestic cats overlapped with the human residential area, where they might secure easy foods. Five of ten tracked cats were active at potential breeding colonies for the Crested Murrlet (Synthliboramphus wumizusume), and six approached potential breeding areas of the Styan's Grasshopper Warbler (Locustella pleskei), suggesting the predation risk of the two endangered species by cats. This study provides novel information on the population size and home range of introduced cats on Mara Islet which is an important stopover site of migratory birds as well as a breeding habitat of the two endangered avian species. Reducing the potential negative impacts of the introduced cats on migratory birds and the endangered species on Mara Islet requires monitoring of the predation rate of birds by cats, the population trends of cats and endangered breeding birds as well as the effective cat population control and management.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.9
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• pp.1217-1224
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• 2006

The registration data of 15 populations from nine major swine breeding farms were investigated to check levels of inbreeding and the current status of pedigree structures of breeding stocks. The average rate of inbreeding per generation was 0.208%, 0.209%, 0.098%, 0.307% and 0.071% for farms D, S, K, H, and Y in Duroc, 0.071%, 0.188%, 0.685%, 0.336%, and 0.449% for farms S, H, C, J, and W in Landrace, and 0.243%, 0.123%, 0.103%, 0.165%, and 0.286% for farms D, S, G, H, and J in Yorkshire, respectively. The average inbreeding rate was highest for Landrace, intermediate for Yorkshire, and lowest for Duroc farms. In Landrace and Yorkshire populations there were few immigrant animals per generation. In Duroc, however, there were quite large numbers of immigrant animals per generation compared to other breeds. The effective population sizes calculated from the average rate of inbreeding were distributed between 73.0 and 708.7. Specific values were 204.8, 239.7, 508.8, 163.0 and 708.2 for farms D, S, K, H, and Y in Duroc, 708.7, 266.5, 73.0, 148.9, and 111.3 for farms S, H, C, J, and W in Landrace, and 205.5, 406.0, 486.9, 302.6 and 175.0 for farms D, S, G, H, and J in Yorkshire, respectively. The values were acceptable for natural selection for fitness and inbreeding depression. The results showed that there was no cause for concern over the current inbreeding level of major swine breeding farm populations and the inbreeding level was within an acceptable range.

• The Korean Journal of Zoology
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• v.27 no.3
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• pp.137-150
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• 1984

The present experiments were carried out to understand the genetic structure of the natural population by means of the frequencies of recessive lethal and sterility genes on the second chromosomes of Drosophila melanogaster. The natural populations used for experiment were Anyang, Kimpo and Ulsan populations in 1982 and 1983. The mean frequencies of deleterious gene (lethal plus semilethal) were estimated 29.01% in Anyang, 30.07% in Kimpo and 32.31% in Ulsan population. Allelism rates on the chromosome between lethals extracted from natural populations were examined within or between populations. The mean allelism rates were showed 2.28% in Anyang, 1.90% in Kimpo and 2.17% in Ulsan. The values of elimination $(IQ^2)$ were estimated by frequencies of deleterious genes and allelism rates. The mean values of elimination were 0.0020 in Anyang, 0.0019 in Kimpo and 0.0023 in Ulsan population. The effective population size was estimated by using a formula by Nei. Anyang, Kimpo and Ulsan populations were about 2, 900, 3, 600 and 3, 200, respecively. These data suggest that Korean populations of Drosophila melanogaster attained to stable breeding units of intermediate size, ranging from 2, 900 to 3, 600 pairs of fertile individuals.

• Journal of Life Science
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• v.24 no.6
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• pp.612-617
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• 2014

The phenetic relationships among six natural populations of Equisetum pratense in Korea were investigated at the population level by constructing a tree based on Random Amplified Polymorphic DNA (RAPD) markers. RAPD analysis was also conducted to estimate genetic diversity and the population structure of E. pratense. A mean of 26.7% at the six population levels indicated polymorphism. E. pratense was found to have fewer alleles per locus (1.267) and fewer effective alleles per locus (1.176). Genetic diversity (0.102) in E. pratense is lower than the average for species with similar life history traits. Total genetic diversity values (HT) varied between 0.112 (OPD-07) and 0.445 (OPD-16), for an average overall polymorphic locus of 0.141. Inter-locus variation in the within-population genetic diversity ($H_S$) was low (0.102). Asexual reproduction, small population size, and the colonization process are proposed as possible factors contributing to the observed low genetic diversity in E. pratense. On a per-locus basis, the proportion of total genetic variation due to differences among populations ($G_{ST}$) ranged from 0.129 for OPD-07 to 0.455 for OPD-09, with a mean of 0.277. This indicated that about 27.7% of the total variation was among populations. Thus, genetic variation (72.3%) resided within populations. This study contributes new information for research on the taxonomy and population genetics of E. pratense.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 2011.04a
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• pp.116-120
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• 2011

With population growth and quality of life improvement, household energy use also has increased. Under this circumstances, consumers are increasingly required to seek for efficient ways of energy saving. However, precedent studies have largely overlooked energy consumers' consumption behavior, and particularly little research has been conducted on energy consumption or saving patterns of residents living in apartments, which account for over 50% of the Korean housing market. Therefore, this study examined apartment residents' energy use behavior according to apartment residents' characteristics in order to efficient energy use and management. To this examination, survey was conducted of housewives living in apartments in Busan, and 403 data were analyzed by the SPSS WIN 12.0 program. With respect to their energy behavior according to characteristics of subjects, it was different depending on income, housing size, age, the length of residence, and the education standard. When higher income group and larger housing size group, residents were not doing 'passive saving' and 'comfort oriented.' When younger, they were 'comfort oriented.' When well-educated, they were 'comfort oriented.' Also, with regard to the length of residence, significant difference was found. The results of this study can be utilized as effective guidelines in efficient management, policy making, and education method reflecting energy use behavior of energy users.

• Asian-Australasian Journal of Animal Sciences
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• v.13 no.9
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• pp.1219-1227
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• 2000

Rumination behavior, in vivo digestibility of cell wall constituents, particle size reduction in the rumen, and retention time in the digestive tract of sheep were examined using rice and oat straw as roughage sources. The in sacco digestibility, rumen fermentation, and microbial population and internal adenosine 5-triphosphate (ATP) content were also determined under feeding conditions of high-roughage and high-concentrate diets. Chewing number and time in rumination behavior were higher with rice straw than with oat straw, while the in sacco and in vivo DMD of rice straw were consistently lower than those of oat straw. Rice straw also showed higher frequency of thinner and longer particles in the rumen contents and lower retention time in the whole digestive tract as compared to those of oat straw. Rice straw was more effective to maintain the ruminal pH than oat straw, being reflected in higher internal ATP content of large-type protozoa on the high- concentrate diet. Changes in the ruminal microflora by shifting from the low- to the high- concentrate diet were also different between rice and oat straw.

• Journal of Distribution Science
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• v.22 no.1
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• pp.1-12
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• 2024

Purpose: Rapid technological advancements and information dissemination have catalyzed a steep upsurge in the distribution of ornamental flower arrangement products, effectively meeting the burgeoning demands of customers. This research endeavours to elucidate the relationship between market orientation (MO) and competitive advantage (CA), with the intermediary role of marketing performance (MP) within Denpasar's flower arrangement retail sector. Research Methods: Conducted within a Denpasar-based flower shop, the study engaged 94 respondents through a questionnaire-based data collection methodology. Utilizing a saturated sampling approach, the sample size equated to the population size. The analysis employed SmartPLS, a robust statistical tool. Results: The study findings reveal that MO does not exert a statistically significant direct impact on CA. Nevertheless, MO exhibits a substantively positive and statistically significant influence on MP, which, in turn, substantially and significantly contributes to CA. For flower arrangement business owners, it is imperative to orchestrate effective control over their marketing performance. Conclusion: This involves nurturing enduring customer and employee relationships by steadily implementing market-oriented distribution strategies. By doing so, customer satisfaction and growth, pivotal in bolstering marketing performance, can be adeptly sustained, ultimately culminating in attaining competitive advantage.

• Communications for Statistical Applications and Methods
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• v.31 no.4
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• pp.377-391
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• 2024

Accurate household projections are essential for sectors such as housing supply and tax policy planning, given the rapid social changes like declining birthrates, an aging population, and a rise in single-person households that impact household size and type. Korea introduced its first register-based census in 2015, transitioning from five-year general survey-based approach to an annual administrative data-based census. This change in census allows for more frequent and effective capturing the rapid demographic shifts and trends. However, this change in census has caused challenges in future projection by the existing household projection model due to the rapid dynamics. This paper proposes a new household projection method, the N-point Modified Exponential Model (MEM), that accurately reflects register-based census data and mitigates the impact of rapid demographic changes, in three types: the Weighted N-point MEM, the Regression-based N-point MEM, and the Rolling Weighted N+point MEM. Using register-based census data from 2016 to 2020 to forecast household headship rates by age, household size, and household type to 2051, the N-point modified exponential model outperformed the existing model in both long- and short-term forecast accuracy, suggesting its suitability as a future household projection model for Korea.

• The Korean Journal of Pesticide Science
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• v.11 no.1
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• pp.46-51
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• 2007

In this study, two commercial mating disruptors were compared in terms of disruption of Oriental fruit moth, Grapholita molesta, male orientation, in which a new dispenser type, $SPLAT^{(R)}$, was compared with a current dispenser type, $Isomate^{(R)}$-M ROSSO. For this assessment, the last three year field monitoring data were analyzed for the efficacy of Isomate type dispenser. Then two commercial dispensers were compared in different localities with sub-locality replications during identical monitoring period from mid February to late August. There appeared to be four adult population peaks, in which the overwintering population size was positively correlated with the following reproductive population sizes. Isomate type dispenser effectively suppressed G. molesta populations during all growing seasons with some annual variation in its efficacy. Between two dispensers, SPLAT type was much effective. The difference in their efficacy may be caused by the difference in composition of major pheromone component.