• Journal of Marine Life Science
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• v.9 no.1
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• pp.9-21
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• 2024

Paralytic shellfish poisoning (PSP) including Saxitoxin (STX) is caused by harmful algae, and poisoning occurs when the contaminated seafood is consumed. The mouse bioassay (MBA), a standard test method for detecting PSP, is being sanctioned in many countries due to its low detection limit and the animal concerns. An alternative to the MBA is the Neuro-2a cell-based assay. This study aimed to establish various test conditions for Neuro-2a assay, including cell density, culture conditions, and STX treatment conditions, to suit the domestic laboratory environment. As a result, the initial cell density was set to 40,000 cells/well and the incubation time to 24 hours. Additionally, the concentration of Ouabain and Veratridine (O/V) was set to 500/50 μM, at which most cells died. In this study, we identified eight concentrations of STX, ranging from 368 to 47,056 fg/μl, which produced an S-shaped dose-response curve when treated with O/V. Through inter-laboratory variability comparison of the Neuro-2a assay, we established five Quality Control Criteria to verify the appropriateness of the experiments and six Data Criteria (Top and Bottom OD, EC₅₀, EC₂₀, Hill slop, and R² of graph) to determine the reliability of the experimental data. The Neuro-2a assay conducted under the established conditions showed an EC₅₀ value of approximately 1,800~3,500 fg/μl. The intra- & inter-lab variability comparison results showed that the coefficients of variation (CVs) for the Quality Control and Data values ranged from 1.98% to 29.15%, confirming the reproducibility of the experiments. This study presented Quality Control Criteria and Data Criteria to assess the appropriateness of the experiments and confirmed the excellent repeatability and reproducibility of the Neuro-2a assay. To apply the Neuro-2a assay as an alternative method for detecting PSP in domestic seafood, it is essential to establish a toxin extraction method from seafood and toxin quantification methods, and perform correlation analysis with MBA and instrumental analysis methods.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.11
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• pp.96-105
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• 2019

This study analyzed the correlation of work values, career attitude maturity and employment preparation behavior by determining the sociodemographic characteristics, and the study confirmed the validity of the influence of work values and career attitude maturity on employment preparation behavior. The subjects of this study were 218 nursing students at a university located in Geonggi-do. The data was collected from June 4th to August 27th, 2019 by using structured questionnaires. As a result, female students scored significantly higher in work values and career attitude maturity than did the male students, and the students who had better grades showed higher employment preparation behavior. In addition, the result showed positive correlation between work values and employment preparation behavior, and the study showed correlation between career attitude maturity and employment preparation behavior. Greater independence, readiness, certainty, and decisiveness were higher and were sub-factors of career attitude maturity and employment preparation behavior. Moreover, the higher the students' patriotism and indoor activities, the higher was their employment preparation behavior. In conclusion, the employment preparation behavior was higher according to greater work values, while the influence of career attitude maturity on employment preparation behavior was not statistically significant.

• Journal of Navigation and Port Research
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• v.30 no.6 s.112
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• pp.471-481
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• 2006

This paper aims to provide strategies to attract container cargoes for the Incheon port by analysing O/D of the container cargoes with the year-2004 export and import data from. The Korean customs service. O/D analysis was carried out with establishing optimal zones, which are defined as City, Gun, Gu(Korean administrative districts) to which the export-import service can be provided from a certain port with minimized freight(or transport) cost and stevedoring fee. For the Incheon port, 35 administrative districts including Seoul and Incheon in Kyunggi-Do and Kangwon-Do are recognized as the optimal zones, and approximately 25.50% of around 2.02-million-TEU per year of the cargoes from the zones are exported and imported through the port. The strategies to attract container cargoes was suggested by comparing the Incheon port to supposed-competitive ports. The Busan port(64.89%), Guangyang port(4.46%) and Pyeongtaeck port(3.35%) are supposed as the competitive ports which have a large proportion of handling the cargoes from the optimal zones. When comparing the Incheon port to these ports. The Incheon port requires a distinctive cost strategy, providing incentives to attract shipping companies and cargoes, improving efficiency related to loading-unloading at the port, and reinforcing Feeder-Network and advertisements about cost-saving to the shippers(the owners of goods) in the national capital region Consequently, the mentioned requirements are suggested as the strategies to attract cargoes for the Incheon port.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.1
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• pp.429-433
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• 2013

Objectives: To explore the correlation between multi-slice spiral CT (MSCT) perfusion parameters and the expression of vascular endothelial growth factor (VEGF) as well as matrix metalloproteinase-2 (MMP-2) in breast cancer. Methods: Forty five breast cancer patients and 16 patients with benign breast tumor, both confirmed by pathology examination, were enrolled. All underwent MSCT perfusion imaging to obtain perfusion maps and data for parameters including blood flow (BF), blood volume (BV) and permeability surface (PS). Cancer patients did not receive treatment prior to surgery. The expression of VEGF and MMP-2 were examined with both immunohistochemistry and Western blotting. Results: The levels of VEGF and MMP-2 by immunohistochemistry were significantly higher in the breast cancer group (P < 0.01) than the benign tumor group. Relative OD values from Western blotting were also higher in cancer cases (P < 0.05). Similarly, the mean MSCT perfusion parameters (BF, BV, PS) were significantly higher in the breast cancer group (P < 0.01), BF and BV positively correlating with VEGF expression (r = 0.878 and 0.809 respectively, P < 0.01); PS and VEGF and MMP-2 expression were also positively correlated (r= 0.860, 0.786 respectively, P < 0.01). Conclusion: There is a correlation between breast cancer MSCT perfusion parameters and VEGF andMMP-2 expression, which might be useful for detection of breast lesions, qualitative diagnosis of breast cancer, and evaluation of breast cancer treatment.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2006.06b
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• pp.289-299
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• 2006

This paper aims to provide strategies to attract container cargoes for the Incheon port by analysing O/D of the container cargoes with the year-2004 export and import data from. The Korean customs service. O/D analysis was carried out with establishing optimal zones, which are defined as City, Gun, Gu(Korean administrative districts) to which the export-import service can be provided from a certain port with minimized freight(or transport) cost and stevedoring fee. For the Incheon port, 35 administrative districts including Seoul and Incheon in Kyunggi-Do and Kangwon-Do are recognized as the optimal zones, and approximately 25.50% of around 2.02-million-TEU per year of the cargoes from the woes are exported and imported through the pan. The strategies to attract container cargoes was suggested by comparing the Incheon port to supposed-competitive pons. The Busan portn(64.89%), Guangyang port(4.46%) and Pyeongtaeck port(3.35%) are supposed as the competitive pons which have a large proportion of handling the cargoes from the optimal zones. When comparing the Incheon port to these ports, The Incheon pan requires a distinctive cost strategy, providing incentives to attract shipping companies and cargoes, improving efficiency related to loading-unloading at the port, and reinforcing Feeder-Network and advertisements about cost-saving to the shippers(the owners of goods) in the national capital region. Consequently, the mentioned requirements are suggested as the strategies to attract cargoes for the Incheon port.

• Clean Technology
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• v.24 no.4
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• pp.269-274
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• 2018

In this study, Life Cycle Assessment (LCA) of wet tissue manufacturing process was performed. The wet tissue manufacturing process consists of preparation of wetting agent (chemical liquid), impregnation of nonwoven fabric into wetting agent and primary and secondary packaging. Data and information were collected on the input and output of the actual process from a certain company and the database of the Korea Ministry of Environment and some foreign countries (when Korean unavailable) were employed to connect the upper and the lower process flow. Based on the above and the potential environmental impacts of the wet tissue manufacturing process were calculated. As a result of the characterization, Ozone Layer Depletion (OD) is 3.46.E-06 kg $CFC_{11}$, Acidification (AD) is 5.11.E-01 kg $SO_2$, Abiotic Resource Depletion (ARD) is $3.52.E+00\;1yr^{-1}$, Global Warming (GW) is 1.04.E+02 kg $CO_2$, Eutrophication (EUT) is 2.31.E-02 kg ${PO_4}^{3-}$, Photochemical Oxide Creation (POC) was 2.22.E-02 kg $C_2H_4$, Human Toxicity (HT) was 1.55.E+00 kg 1,4 DCB and Terrestrial Ecotoxicity (ET) was 5.82.E-04 kg 1,4 DCB. In order to reduce the environmental impact of the manufacturing process, it is necessary to improve the overall process as other general cases and change the raw materials including packaging materials with less environmental impact. Conclusively, the energy consumed in the manufacturing process has emerged as a major issue, and this needs to be reconsidered other options such as alternative energy. Therefore, it is recommended that a process system should be redesigned to improve energy efficiency and to change to an energy source with lower environmental impact. Due to the nature of LCA, the final results of this study can be varied to some extent depending on the type of LCI DB employed and may not represent of all wet tissue manufacturing processes in the current industry.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.18 no.1
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• pp.1-13
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• 2019

With commercial apps popular in EU, MaaS has been emerging around the globe as a new approach to worsening urban traffic problems. In contrast, it is still mainstay in Korea simply discussing the concept and necessities of MaaS, rather than seeking for real-world solutions for the commercialization. The purpose of this research is to analyze the demand-side i1mpacts of travel time and cost changes according to MaaS adoption, and to see its commercial feasibility in Korea. The 2010 KTDB traveler's nationwide OD data is used to estimate the level of fare discount for balancing the mode shift and fare revenue changes followed by MaaS implementation. The analysis results show that MaaS leads to the increase of public transport ridership as a result of the diminishing travel cost and time, and that the time saving works more positively for ridership increase. Also, the optimum level of fare discount is estimated 2.56% without damaging the revenue. This finding reveals that MaaS impact is superior to the other single-sided public transport inventive measures since it can affect both travel cost and time reduction at the same time.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.9
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• pp.167-174
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• 2019

The propose od this study was to examine the extent of using physical restraint on elderly patients (over 65 years old) and who were patients in long-term care hospitals. The data was collected, from March 3 2018 to March 29 2018, from the electronic nursing records by using a recording tool, and clinical observation was also used for assessing the use of physical restraint and the related factors. Descriptive statistics, Pearson correlation coefficients and logistic regression were then performed. The usage rate for physical restraints in long-term care hospital was 83.7%, and the most common type of physical restraint was side rails. The use of physical restraints showed a positive correlation with the fall risk scores and a negative correlation with the MMSE. Logistic regression analysis showed that the Fall Risk Score (OR=1.02, 95% CI=1.01~1.03), MMSE (OR=0.94, CI=0.88~0.99) and the use of medical devices (OR=0.80, 95% CI=0.65~0.98) were related with using physical restraints. Therefore, it was confirmed that physical restraint was used in cases of a high risk of falling, severe cognitive impairment and the use of complex and fragile medical devices to treat the patient. Clinical nursing practice should be changed so that treatment alternatives can be applied for elderly patients rather than using too many physical restraints.

• Journal of Life Science
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• v.29 no.10
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• pp.1111-1119
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• 2019

Prunus mume, known as maesil in Korea, has been widely cultivated in East Asia and used as medication and food. However, because most of the previous studies concerning P. mume had been investigated its under extract state, detailed studies are still required for its extensive utilization. In this study, we evaluated the antioxidant and ${\alpha}-glucosidase$ inhibitory activities of solvent fractions of P. mume ethanol extracts. The ethyl acetate fraction showed higher DPPH radical scavenging activity, ABTS radical scavenging activity, reducing power, and hydrogen peroxide scavenging activity than other fractions. The DPPH radical scavenging activities of ethyl acetate fraction was 67.79%; ABTS radical scavenging activity was 60.03%; reducing power ($OD_{670}$) was 1.26; and hydrogen peroxide scavenging activity was 93.18% at $500{\mu}g/ml$. Also, the ethyl acetate and methanol fraction showed effective levels of ${\alpha}-glucosidase$ inhibition activity (69.25% and 72.29% at $500{\mu}g/ml$). Total polyphenol contents and total flavonoid contents of the ethyl acetate fraction were 88.28 mg/g (gallic acid equivalent) and 70.38 mg/g (quercetin equivalent), respectively. These results suggest that the physiological activities of the ethyl acetate fraction are associated with its polyphenol and flavonoid contents. Therefore, this study can be used as basic data for developing natural antioxidants and potential functional material using P. mume.

• Journal of Industrial Convergence
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• v.20 no.9
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• pp.25-38
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• 2022

The purpose of this paper is to verify the cost behavior of non-listed companies in Mongolia from 2013 to 2018. And we investigate the relationship between cost behavior and earnings management. Earnings management was measured using the Big-Bath and avoiding loss incentives. Big-Bath suspected firms report a very large loss and avoiding loss suspected firms have a bite profit. The results of this study are as follows. First, non-listed firms in Mongolia, operating costs(oc) and selling, general and administrative(sga) costs show the cost stickiness. Second, cost stickiness was different depending on the earnings management. The suspected avoiding loss firms have upward earnings management incentives, operating costs and sga costs all present anti-cost stickiness. The suspected big bath firms strengthen the cost stickiness of operating costs and sga costs. This study is meaningful in that it first analyzed the relationship between earnings management and cost stickiness of non-listed firms in Mongolia using empirical data. It will be meaningful in that it provides relevant information to those interested in research and investment.