• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.17 no.5
• /
• pp.123-130
• /
• 2018

In this study, the optimum design of mold feed systems is determined for plug cover housing (PCH), which is a cover-assembly product that protects the wiring of automobile connectors. The design goal is to achieve the filling balance of the resin in the left and right covers while avoiding the occurrence of weld lines in the hinge as much as possible. For the optimization, an orthogonal array experiment and a main effect analysis of the design factors are performed, and the factors that cause the interactions with the two design characteristics are selected as the design variables. We present some design alternatives, i.e., some combinations of the design variables, and analyze the filling-simulation results, expected molding risk, and cost economics to select an optimum design solution among the design alternatives. In the optimal solution, the weld line is generated at a position outside the hinge, and the filling balance is also acceptable, showing that both design goals can be satisfied simultaneously despite conflicting with each other.

• Nuclear Engineering and Technology
• /
• v.51 no.2
• /
• pp.607-617
• /
• 2019

Global warming and climate change are increasing the intensity of typhoons and hurricanes and thus increasing the risk effects of typhoon and hurricane hazards on nuclear power plants (NPPs). To reflect these changes, a new NPP should be designed to endure design-basis hurricane wind speeds corresponding to an exceedance frequency of $10^{-7}/yr$. However, the short typhoon and hurricane observation records and uncertainties included in the inputs for an estimation cause significant uncertainty in the estimated wind speeds for return periods of longer than 100,000 years. A logic-tree framework is introduced to handle the epistemic uncertainty when estimating wind speeds. Three key parameters of a typhoon wind field model, i.e., the central pressure difference, pressure profile parameter, and radius to maximum wind, are used for constructing logic tree branches. The wind speeds of the simulated typhoons and the probable maximum wind speeds are estimated using Monte Carlo simulations, and wind hazard curves are derived as a function of the annual exceedance probability or return period. A logic tree decreases the epistemic uncertainty included in the wind intensity models and provides reasonably acceptable wind speeds.

• Infection and chemotherapy
• /
• v.50 no.4
• /
• pp.301-310
• /
• 2018

Backgroud: Influenza vaccination is recommended for adults aged ${\geq}65$ years as they are at high risk of significant morbidity and mortality. This open-label, multicenter, post-marketing surveillance study assessed the safety of the MF59-adjuvanted trivalent inactivated subunit influenza vaccine, which is marketed as $FLUAD^{(R)}$ and $VANTAFLU^{(R)}$, in South Korean subjects aged ${\geq}65$ years. Materials and Methods: Solicited local and systemic adverse events (AEs) were collected from day 1 to 4 of the study. All unsolicited AEs and serious AEs (SAEs) were recorded from day 1 until study termination (day 29). Results: Of the 770 subjects enrolled ($FLUAD^{(R)}$, n = 389; $VANTAFLU^{(R)}$, n = 381), 39% overall experienced any solicited AE. Local AEs were reported by 33% of subjects overall; with the most common events being injection-site pain (30%) and tenderness (27%). Systemic AEs were reported by 19% of subjects overall with the most common events being myalgia (11%) and fatigue (8%). Conclusion: These results show that the MF59-adjuvanted influenza vaccine known as $FLUAD^{(R)}$ or $VANTAFLU^{(R)}$ had acceptable safety profiles in older adults (aged ${\geq}65$ years) in South Korea.

• The Korean Journal of Food And Nutrition
• /
• v.35 no.6
• /
• pp.543-551
• /
• 2022

There has been increased interest in lignans due to their potential effect in reducing the risk of developing several diseases. To evaluate lignan contents, sensitive and accurate methods should be developed for their quantification in food. The present study aimed to validate a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the quantification of 5 lignans: lariciresinol (Lar), matairesinol (Mat), pinoresinol (Pin), secoisolariciresinol (Seco), and syringaresinol (Syr). The validation included selectivity, linearity, recovery, accuracy, and precision. The method was proved to be specific, with a linear response (R²≥0.99). The limits of detection were 0.040~0.765 ㎍/100 g and the limits of quantification were 0.114~1.532 ㎍/100 g. Recoveries were 90.588~109.053% for black sesame powder. Relative standard deviations of repeatability and reproducibility were below 5%. Total lignan contents of roasted coffee bean, oat, and blacksoy bean were 105.702 ㎍/100 g, 78.965 ㎍/100 g, and 165.521 ㎍/100 g, respectively. These results showed that LC-MS/MS analysis would be effective in producing acceptable sensitivity, accuracy, and precision in five lignan analyses.

• The Journal of Engineering Geology
• /
• v.31 no.4
• /
• pp.463-478
• /
• 2021

The subjects of the study are the sedimentary rock slope of the Mesozoic Gyeongsang Supergroup, which has a high risk of failure. The orientation of the slope-face represents a variety of changing characteristics. The rocks of the slope shall be sandstone, siltstone and dacite, and discontinuities shall develop beddings, shear joints, extension joints, and dacite dyke boundary planes. The type and scale of failure varies depending on the type of rock and the strike/dip of the discontinuities, but the toppling failure prevails. Based on the face-mapping data, SMR, physical and mechanical testing of rocks, analysis and review of the stereonet projections and the critical equilibrium analysis, all four representative sections required a countermeasure method because the acceptable safety factor during dry and rainy seasons were far below Fs = 1.5 and Fs = 1.2. After applying the countermeasure method, both the dry and wet conditions of the slope exceeded the allowable safety factor. In particular, the face-mapping data of the slope-face, the geological cross-sections of several representative sections perpendicular to the slope-face, and the critical equilibrium analysis and the presentation of countermeasure methods that have been reviewed based on them are expected to be reasonable tools for the slope stability. In addition, it will be possible to use it as basic data for performance evaluation for slope maintenance.

• International Journal of Stem Cells
• /
• v.16 no.1
• /
• pp.16-26
• /
• 2023

Despite long-term research achievements, the development of cell therapy (CT) products remains challenging. This is because the risks experienced by the subject and therapeutic effects in the clinical trial stage are unclear due to the various uncertainties of CT when administered to humans. Nevertheless, as autologous cell products for systemic administration have recently been approved for marketing, CT product development is accelerating, particularly in the field of unmet medical needs. The human experience of CT remains insufficient compared with other classes of pharmaceuticals, while there are countless products for clinical development. Therefore, for many sponsors, understanding the rationale of human application of an investigational product based on the consensus and improving the ability to apply it appropriately for CT are necessary. Thus, defining the level of evidence for safety and efficacy fundamentally required for initiating the clinical development and preparing it using a reliable method for CT. Furthermore, the expertise should be strengthened in the design of the first-in-human trial, such as the starting dose and dose-escalation plan, based on a sufficiently acceptable rationale. Cultivating development professionals with these skills will increase the opportunity for more candidates to enter the clinical development phase.

• The Korean Society of Law and Medicine
• /
• v.23 no.3
• /
• pp.139-207
• /
• 2022

As various state restrictions on individual freedom were imposed during the COVID-19 pandemic, concerns have been raised that excessive infringements on fundamental rights were indiscriminately permitted based on the public interest of preventing infectious diseases. Therefore, the question of how to set acceptable limits of liberty restrictions on individuals has emerged. However, since the phenomenon of infections spreading to the population is only predicted statistically, how to deal with the risk of the infected individual as a subject of legal analysis has become a problem. In the absence of a theoretical framework of legal analysis of risk, the risk of infected individuals during the pandemic was not analyzed strictly, and proportionality review of infection prevention measures was often only an abstract comparison of the importance of public interest and individual rights. Therefore, this research aims to conduct a theoretical review on how risk can be conceptualized legally in a public health crisis, and to develop a theoretical framework for proportionality review of the risk of liberty-limiting measures during a pandemic. Chapter 2 analyzes the legal philosophical concepts of risk, which are the basis for liberty restrictions during a public health crisis, and applies and extends them to the pandemic. Chapter 3 reviews previous studies related to liberty restriction measures in the context of the COVID-19 pandemic, and points out they have a limitation that specific criteria for the proportionality review of public health measures in the pandemic have not been presented. Accordingly, Chapter 3 specifies the methodological framework for proportionality review, referring to the theoretical discussion on risks in Chapter 2. Chapter 4 reviews the legitimacy of gathering restriction orders, applying the theoretical discussion in Chapter 2 and the criteria for proportionality review established in Chapter 3. In particular, Section 4 examines logic of proportionality review in judicial precedents over the ban on gathering restrictions implemented in the COVID-19 pandemic. In analyzing the precedents, the logic of proportionality review in each case is critically reviewed and reconstructed based on the theoretical framework presented in this research.

• Journal of Environmental Impact Assessment
• /
• v.25 no.6
• /
• pp.414-431
• /
• 2016

There are numerous closed and abandoned mines in Korea, from which diverse heavy metals (e.g., As, Cd, Cu, Pb, Zn) are released into the surrounding soil, groundwater, surface water, and crops, potentially resulting in detrimental effects on the health of nearby residents. Therefore, we performed human risk assessments of two abandoned metal mines, Yanggok (YG) and Samsanjeil (SJ). The exposure parameters used in this assessment were specific to residents near mines and the included exposure pathways were relevant to areas around metal mines. The computed total excess carcinogenic risks for both areas exceeded the acceptable carcinogenic risk ($1{\times}10^{-6}$), indicating that these areas are likely unsafe due to a carcinogenic hazard. In contrast, the non-carcinogenic risks of the two areas differed among the studied receptors. The hazard indices were higher than the unit risk (=1.0) for male and female adults in YG and male adults in SJ, suggesting that there are non-carcinogenic risks for these groups in the study areas. However, the hazard indices for children in YG and female adults and children in SJ were lower than the unit risk. Consumption of groundwater and crops grown in the area were identified as major exposure pathways for carcinogenic and non-carcinogenic hazards in both areas. Finally, the dominant metals contributing to carcinogenic and non-carcinogenic risks were As and As, Cu, and Pb, respectively. In addition, the carcinogenic and non-carcinogenic risks of YG were evaluated to be 10 and 4 times higher than those of SJ, respectively, resulted from the relatively higher exposure concentration of As in groundwater within SJ area. Because of lacking of several exposure parameters, some of average daily dose (ADD) could not be computed in this study. Furthermore, it is likely that the ADDs of crop-intake pathway included some errors because they were calculated using soil exposure concentrations and bioconcentration factor (BCF) rather than using crop exposure concentrations.

• Journal of Nutrition and Health
• /
• v.47 no.4
• /
• pp.247-257
• /
• 2014

Purpose: It is reported that most senior people consume a high carbohydrate diet, while a high carbohydrate diet could contribute to the risk of chronic disease. The aim of this study is to determine whether a high carbohydrate diet can increase the risk of chronic disease in elderly Koreans. Methods: Using the 2007-2009 Korean National Health Nutrition Examination Survey data, out of a total of 3,917 individuals aged 65 and above, final 1,535 subjects were analyzed, divided by dietary carbohydrate energy ratio into two groups of moderate carbohydrate ratio (MCR, 55-70%) and excessive carbohydrate ratio (ECR, > 70%). All data were processed after the application of weighted value, using a general linear model or logistic regression. Results: Eighty one percent of elderly Koreans consumed diets with carbohydrate energy ratio above 70%. The ECR group included more female subjects, rural residents, lower income, and lower education level. The ECR group showed lower waist circumference, lower diastolic blood pressure, and lower frequency of consumption of meat and egg, milk, and alcohol. The intake of energy and most nutrients, with the exception of fiber, potassium, vitamin A, and carotene, was lower in the ECR group compared to the MCR group. When analyzed by gender, the ECR group showed lower risk of dyslipidemia in male and obesity in female subjects, even though the ECR group showed low intake of some nutrients. No difference in the risk of hypertension, diabetes, and anemia was observed between the two groups in male or female subjects. Conclusion: This result suggested that a high carbohydrate diet would not be a cause to increase the risk of chronic disease in the elderly. Further study is needed in order to determine an appropriate carbohydrate energy ratio for elderly Koreans to reduce the risk of chronic disease.

• Journal of Food Hygiene and Safety
• /
• v.28 no.1
• /
• pp.13-18
• /
• 2013

This study was conducted to monitor residual pesticides in ginseng and balloon flower roots and to assess their risk to human health. All of 112 samples consisted of ginseng and balloon roots were purchased from traditional domestic markets and supermarkets in nine provinces of Korea in 2012. Multi-residue analysis of 122 pesticides was conducted and the analysis was performed by gas chromatography-electron capture detector, gas chromatography- nitrogen/phosphorus detector, and high-performance liquid chromatography. Seven pesticides were detected in 12 root samples and the detection rate was 10.7%. The detected twelve root samples were 10 ginseng root samples and 2 balloon root samples. Pesticides detected in root samples were procymidone, kresoxim-methyl, endosulfan, cypermethrin, tralomethrin, tetraconazole and chlorfluazuron. Among them, two pesticides as tetraconazole in a balloon flower root and cypermethrin in a ginseng root exceeded the recommended maximum residue limit set by Korea Food and Drug Administration. Five pesticides detected from 10 root samples were identified as unregistered pesticides in Korea. In order to do risk assessment with Korean medicinal plant consumption, estimated daily intake of residual pesticides were determined and compared to acceptable daily intake, referring to %ADI values. The range of %ADI values was from 0.006% to 0.333%. Taken together, it demonstrates the pesticides found in the two root samples were below the safety margin, indicating no effect on human health.