• Korean Journal of Applied Biomechanics
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• v.31 no.2
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• pp.133-139
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• 2021

Objective: This study aims to verify the conventional deadlift motions using by two different grips, thereby elucidating the grounds for effective training methods that can minimize the risk of injury. Method: Total of 18 healthy young adults were recruited for this study (age: 25.11±2.19 yrs., height: 175.67±5.22 cm, body mass: 78.5±8.09 kg, 1-RM: 125.75±19.48 kg). All participants were asked to perform conventional deadlift with two types of grips which are overhand grip (OG) and underhand grip (UG). In each grip, participant perform the deadlift with 50% and 80% of the pre-measured 1-RM. A 3-dimensional motion analysis with 8 infrared cameras and 3 channels of EMG was performed in this study. A two-way ANOVA (group × load) with repeated measure was used for statistical verification. The significant level was set at α=.05. Results: There were significant differences in grip type and weight on the right shoulder joint, and only significant difference in grip on the left shoulder joint (p<.05). The hip joint ROM was significantly increased as the weight increased in both types of grips on phase 1, while the ROM of hip joint was significantly decreased as the weight increased only in the case of OG on phase 2 (p<.05). In case of the OG, as the weight, increased significantly increased L1 ROM and L3 ROM were revealed on phase 1 and phase 2, respectively (p<.05). Moreover, as the weight increased, UG revealed significantly decreased L5 ROM on phase 1, while both grips showed significantly increased ROM on phase 2 (p<.05). In addition, the erector spinae and the biceps femoris, which are synergist for the motion, showed a significant difference in both types of grip according to the weight (p<.05). The muscle activity ratio of gluteus maximus/biceps femoris showed a significant difference only in the UG according to the weight (p<.05). Conclusion: In conclusion, beginners might be suggested to use the UG for maintaining the neutral state of the lumbar spine and focus on the gluteus maximus muscle, which is the main activation muscle. For the experts, it may recommend alternative use of the OG and UG according to the training purpose to minimize the compensation effect.

• Journal of Korea Trade
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• v.25 no.5
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• pp.39-57
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• 2021

Purpose - This research uses ocean marine insurance (OMI) statistics, international emails, focus-group interviews, and surveys to fill the gap between the theory of behavioral insurance, particularly status quo bias (SQB), and the practice of OMI in Korea. The contractual forms of OMI, the oldest and most globalized form of commercial insurance, were developed in the UK as the Institute Cargo Clauses in 1906 and revised in 1963, 1982, and 2009. SQB has been academically explored, mostly in health insurance and the financial services sector, but never in OMI. Thanks to the availability of OMI statistics in Korea, we can conduct SQB research here for the first time in this field. Design/methodology - We show the existence of SQB in the OMI of Korea through Korean statistics between 2009 and 2018, email correspondence with experts in the UK, Germany, and Japan, focus-group interviews with Korean OMI underwriters, an in-depth interview with one underwriter, and a survey of 15 OMI insureds (company representatives). Findings - We find that Korean foreign traders rely on the old-type OMI contracts developed in 1963, whereas other industrialized countries use the newest type of OMI contract developed in 2009. With a simple loss ratio analysis during 2009-2018, we show that the behavior of insurers has little to do with rational profit maximization and is instead driven by irrational bias, as they forgo the more profitable contracts provided by the new clauses by keeping the old clauses. The consistent addiction to old types of contracts in the OMI market suggests strong SQB among Korean exporters, importers, bankers, or insurers, which we confirmed in our interviews and survey. Originality/value - This research has significant originality and academic value because it reports new findings with crucial implications for the development of efficient trade practices and policy. First, this research is based on actual statistics that have not been used in previous Korean research on OMI. Second, this research shows that all-risk OMI policies provide more value to insureds, in terms of coverage given premium, than partial coverage policies, which differs from arguments previously made in Korea. Third, this research reveals strong SQB in Korea, where foreign trade plays a pivotal role in economic growth. That bias could be attributable to uninformed traders, informed but idle insurers, or conservative bankers. Fourth, to further develop foreign trade, policy initiatives are needed to review the current practices of OMI contracts and move forward with the new contract forms. All of these findings and arguments are both new and important.

• The Journal of Engineering Geology
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• v.31 no.3
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• pp.381-393
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• 2021

Physical, mechanical, hydraulic, and geophysical tests were applied to validate methods of inspecting the effectiveness of grouting on an agricultural reservoir dam. Data obtained from series of in situ and laboratory tests considered four stages: before grouting; during grouting; immediately after grouting; and after aging the grouting for 28 days. The results of SPT and triaxial tests, including the unit weight, compressive strength, friction angle, cohesion, and N-value, indicated the extent of ground improvement with respect to grout injection. However, they sometimes contained errors caused by ground heterogeneity. Hydraulic conductivity obtained from in situ variable head permeability testing is most suitable for identifying the effectiveness of grouting because the impermeability of the ground increased immediately after grouting. Electric resistivity surveying is useful for finding a saturated zone and a seepage pathway, and multichannel analysis of surface waves (MASW) is suitable for analyzing the effectiveness of grouting, as elastic velocity increases distinctly after grouting injection. MASW also allows calculation from the P- and S- wave velocities of dynamic properties (e.g., dynamic elastic modulus and dynamic Poisson's ratio), which can be used in the seismic design of dam structures.

• Health Policy and Management
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• v.30 no.4
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• pp.493-504
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• 2020

Background: There have been many studies on the associations between body mass index (BMI) and cognitive function. However, no study has ever compared the associations across the methods of categorizing BMI. In this study, we aimed to fill the gap in the previous studies and examine whether the obesity paradox is valid in the risk of cognitive function. Methods: Of the 10,254 people aged 45 and older from the Korean Longitudinal Study of Ageing from 2006 to 2016, 8,970 people were finalized as the study population. The dependent variable was whether a person has a normal cognitive function or not, and the independent variables of interest were BMI categorized by the World Health Organization Western Pacific Regional Office (WHO-WPRO) method, the WHO method, and a 10-group method. Covariates included sociodemographic factors, health behavior factors, and health status factors. A generalized linear mixed model analysis with a logit link was used. Results: In the adjusted model with all covariates, first, in the case of BMI categories of the WHO-WPRO method, underweight (odds ratio [OR], 1.16; 95% confidence interval [CI], 1.15-1.17), overweight (OR, 1.36; 95% CI, 1.35-1.36), and obese (OR, 1.34; 95% CI, 1.33-1.34) groups were more likely to have a normal cognitive function than a normal-weight group. Next, in the case of BMI categories of the WHO method, compared to a normal-weight group, underweight (OR, 1.15; 95% CI, 1.14-1.16) and overweight (OR, 1.06; 95% CI, 1.06-1.07) groups were more likely to have a normal cognitive function; however, obese (OR, 0.62; 95% CI, 0.61-0.63) group was less likely to have it. Lastly, in the case of the 10-group method, as BMI increased, the likelihood to have a normal cognitive function changed like a wave, reaching a global top at group-7 (26.5 kg/㎡ ≤ BMI <28.0 kg/㎡). Conclusion: The associations between BMI and cognitive function differed according to how BMI was categorized among people aged 45 and older in Korea, which suggests that cognitive function may be positively associated with BMI in some categories of BMI but negatively in its other categories. Health policies to reduce cognitive impairment need to consider this association between BMI and cognitive function.

• Biomedical Science Letters
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• v.26 no.4
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• pp.344-350
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• 2020

Asthma is a chronic disease and occurs in airway in the lung. The cause of the disease has not been identified, it is assumed that both genetic and environmental risk factors play an important role in the development of asthma. Interleukin (IL)-12 is a cytokine regulating T-cell and NK cell. In this study, we analyzed the genetic polymorphisms of IL-12 receptor genes (IL-12Rβ1 and IL-12Rβ2) in asthma patients and normal individuals in a Korean population. We analyzed single nucleotide polymorphisms (SNPs) in IL-12Rβ1 and IL-12Rβ2 using the genotype data of 193 asthma cases and 3,228 healthy controls from the Korea Association REsource for their correlation with asthma case. IL-12Rβ1 and IL-12Rβ2 genes showed statistically significant polymorphism association with asthma case. As a results, 16 SNPs from IL-12Rβ1 and IL-12Rβ2 genes showed statistically significant association with asthma. Among them, rs375947 SNP in IL-12Rβ1 showed the greatest statistical correlation with asthma (P-value = 0.028, Odds Ratio = 1.27, 95% Confidence Interval = 1.03~1.57). The groups with minor allele of IL-12Rβ1 and IL-12Rβ2 showed increased risk of asthma. The genotype-based mRNA expression analysis showed that the group of minor allele of IL-12Rβ1 showed decreased mRNA expression. Decreased IL-12Rβ1 expression causes decreased IL-12 signaling, and this affects developing asthma. In conclusion, the SNPs in IL-12Rβ1 and IL-12Rβ2 may contribute to development of asthma in a Korean population.

• Korean Journal of Food Science and Technology
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• v.53 no.1
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• pp.40-45
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• 2021

Prior studies of physiologically active substances in grapes have focused only on the fruit, pericarp, and branches, as well as the pulp and seeds. The present study assessed the changes in quercetin-3-O-glucuronide (Q3OG) and flavonol glycoside content using grape leaves from Vitis labruscana B. and V. coignetiae at different growth stages and provided basic data for quality control. Content analysis showed that both varieties differed in Q3OG and flavonol glycoside content by growth stage, and the components were found to be high in the order of fruit, maturation, and coloration. Also, Vitis labruscana B. has a better vascular relaxation effect than Vitis coignetiae. These results suggest that in the use of grape leaves as a functional raw material, Q3OG and flavonol glycosides can be used as indicator components. In addition, if raw materials for each growth stage are mixed in a particular ratio, it will be a way to manage the specific efficacy and content of indicator components.

• Journal of the Architectural Institute of Korea Planning & Design
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• v.34 no.1
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• pp.3-14
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• 2018

An apartment complex is a building use with great potential to contribute to solving problems related to urban ecological environment and climate change. The first goal of this study is to grasp the current situation of application and limitations of the ecological area rate, which is a representative evaluation index used to evaluate the environmental performance of the external space of an apartment complex in Green Standard for Energy and Environmental Design (G-SEED). The second goal is to propose a prototype of the evaluation index for evaluating greenhouse gas (GHG) reduction performance in order to supplement the evaluation index for the environmental performance of the external space in terms of response to climate change. We analyzed 43 cases of apartment complexes certified according to G-SEED, which was enforced since July 1, 2010, and found application characteristics of each space type and the limitations of ecological area rate. We analyzed overseas green building certification systems such as LEED and BREEAM that derived implications for supplementing the limitations of ecological area rate, which is focused on the evaluation of soil and water circulation function, and set up a development direction of complementary measures. Through analysis of previous studies, relevant regulations and standards, and technical documents of the manufacturer, the heat island mitigation performance of the pavement and roof surfaces of the apartment complex and the carbon uptake performance of the trees in the apartment complex was selected as parameters to yield the GHG reduction performance of the external space of the apartment complex. Finally, a quantitative evaluation method for each parameter and a prototype of the evaluation index for the GHG reduction performance were proposed. As a result of applying the prototype to an apartment complex case, the possibility of adoption and applicability as an evaluation index of G-SEED were proved.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.2
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• pp.434-439
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• 2021

We assessed the effects of intravenous (IV) ascorbic acid administration on fatigue in women undergoing laparoscopic myomectomy. We analyzed the secondary endpoint results of a randomized, double-blind, placebo-controlled trial. Fifty patients undergoing laparoscopic myomectomy received IV ascorbic acid (2g) or placebo (randomly 1:1 ratio) intravenously during surgery. On day 2 post-surgery, we measured the level of fatigue using the Brief Fatigue Inventory-Korean version. Forty-five women (experimental arm 23, control arm 22) were eligible for analysis after 5 women (experimental arm 2, control arm 3) were excluded due to withdrawal of consent, cancellation of surgery or non-measurement of the endpoints. The baseline and operative characteristics were similar between arms and the global fatigue score of the experimental arm (4.56 ± 2.63) was not significantly different from that of the control arm (5.21 ± 2.02, P = 0.351). However, the fatigue score of the experimental arm tended to be lower than that of the control arm in most domains. IV ascorbic acid administration did not significantly reduce the level of fatigue in women undergoing laparoscopic myomectomy as compared to placebo. More research is needed to better understand the effects of ascorbic acid on fatigue in surgical patients.

• Resources Recycling
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• v.29 no.6
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• pp.65-72
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• 2020

Black dross is a dark gray dross generated during the aluminum recycling process that uses flux, and contains NaCl, KCl, Al2O3, MgO, etc. Black dross is separated into soluble substances (NaCl, KCl) and insoluble substances (Al2O4, MgO) through the dissolution process. Soluble materials can be reused as salt flux, and Al2O3 and MgO can be upcycled to various ceramic materials through the synthesis process. In this study, Mayenite was synthesized using Al2O3 and MgO recovered from black dross, and the synthesis was performed according to the mixing ratio and reaction temperature. It was confirmed that when Mayenite was synthesized using black dross (spinel) and CaCO3, precursors were changed to Mg0.4Al2.4O4 and CaO at 700 ℃, and to Ca12Al14O33 (Mayenite) after 800 ℃. In the mixing conditions experiment, it was confirmed that the Mayenite XRD peak increased with increase of the CaCO3 content, and the Mg0.4Al2.4O4 XRD peak decreased. As a result of the BET analysis of the synthesized powder, the surface area decreased as the fine particles were grown and agglomerated in the process of generating mayenite.

• Journal of Navigation and Port Research
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• v.44 no.6
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• pp.541-549
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• 2020

This study conducts differential analysis on the financial positions of Korean shipping companies before and after the bankruptcy of the H carrier, looking specifically at their financial ratios, profit and loss patterns, and other factors related to their financial operation. Firstly, it was discovered that major measures of financial health, such as average assets per carrier, were not affected by the bankruptcy of the H carrier. However, despite this, most carriers experienced large changes in profits and losses, with total sales and shipping revenues averaging 424.5 billion won and 381.7 billion won respectively before the bankruptcy, but falling by half to 252.1 billion won and 234.6 billion won after the bankruptcy. Additionally, charter revenues and expenses also dropped by more than half. EBIT/sales and pre-tax revenue margins were also heavily affected after the bankruptcy, with both figures averaging 8% and 3% respectively before the bankruptcy, but falling into the negative range at -2% and -8% post-bankruptcy, resulting in significant deterioration in operational profitability. The study concludes that there is an urgent need to establish a global sales network, improve cost structures, and consistently secure stable cargo in order to increase Korean carriers' profitability. Of all financial measures, liquidity and total asset efficiency were identified as the most severely-impacted by the H carrier bankruptcy, thereby requiring the most pressing policy addressing.