• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.19 no.11
• /
• pp.750-757
• /
• 2018

The mechanically stabilized earth wall abutment is an earth structure using a mechanically stabilized earth wall and it uses in-extensional steel reinforcements having excellent friction performance. In order to analyze the pullout behavior of in-extensional steel reinforcements usually applied on the mechanically stabilized earth wall abutment, effects of stiffness and particle-size distributions of backfills and also horizontal spacings were considered in this study. As a result of parametric analyses, the highest pulling force acted on the uppermost reinforcement, and the stiffness and the particle-size distributions of the backfill significantly affected the pulling resistance of the reinforced soils. The internal friction angle of backfills should be at least 25 degrees, the coefficient uniformity factor should be at least 4, and the horizontal spacing of the uppermost steel reinforcement should be less than 25cm. Therefore, in order to secure the pullout resistance of the reinforced soil, it is necessary a properly spacing of reinforcement and more strict quality control for the backfill.

• Korean Journal of Clinical Laboratory Science
• /
• v.51 no.1
• /
• pp.93-104
• /
• 2019

This study examined the relationship between the number of medical technologists and the medical test count. Data was obtained from 441 medical technologists in a hospital through a self-reported questionnaire. The Pearson correlation test, student's t-test, ANOVA or descriptive statistics were performed for data analysis. The distribution of medical technologist according to the size of hospitals was small 5.8, medium 14.9, large 25.8, and super 45.4. The analysis demonstrated a relationship between the number of medical technologists and the number of medical tests in the field, number of clinical tests per MT, and number of optimal medical test per MT according to the hospital size (P<0.001). The average time for quality control by the department at a higher hospital was less than two hours. In terms of the satisfaction of salary, work environment, test accomplishment, and welfare service, the dissatisfaction of medical technologists in small and medium hospitals was higher than those in large and super hospitals. Overall, a focus on intensifying systemic supplementation and improving the condition of medical technologists is needed to provide reliable data for medical examinations in medical areas.

• Tunnel and Underground Space
• /
• v.28 no.6
• /
• pp.609-619
• /
• 2018

This study was carried out at a local limestone mine to analyze the ventilation efficiency of the shaft equipped with a main fan. The results show that its ventilation efficiency is clearly verified for the natural as well as the mechanical ventilation. The airflow rate of $11.7m^3/s$ was induced by the natural ventilation force and the maximum quantity is almost same as the airflow rate estimated by monitoring the average temperatures in the upcast and downcast air columns. Meanwhile, the airflow rate exhausted by the main fan through the shaft was $20.3{\sim}24.8m^3/s$; variation of the quantity was caused by the upward shift of the mine ventilation characteristic curve due to the frequent movement of the equipment. This indicates efforts are required to reduce the ventilation resistance and raise the quantity supplied by the main fan. The turbulent diffusion coefficients along the 1912 m long airway from the portal to the shaft bottom was estimated to be $15m^2/s$ and $18m^2/s$. Since these higher coefficients imply that contaminants will be dispersed at a faster velocity than the airflow, prompt exhaust method should be planned for the effective air quality control. The ventilation shaft and main fan are definitely what local limestone mines inevitably need for better working environment and sustainable development.

• Journal of Navigation and Port Research
• /
• v.44 no.6
• /
• pp.439-446
• /
• 2020

The IMO has adopted emission standards through Annex VI of the International Convention for the Prevention of Pollution from Ships (MARPOL) that strictly prohibit the use of bunker C oil for vessels. In this study, we have adopted the turret-moored Floating LNG-Bunkering Terminal (FLBT) which is designed to receive the LNG from LNGCs and transfer it to LNG-bunkering shuttles in side-by-side moored condition. Numerical analyses were carried out using the high-order boundary-element method for four vessels at various relative distances. Mean wave drift forces were compared in an operational sea state. A model test was performed in the ocean engineering basin at the Korea Research Institute of Ships & Ocean Engineering (KRISO) to verify the safety of the berthing/unberthing operation. In the model test, a jig was designed to simulate tug boats pushing or pulling the bunkering vessels, so that the friction force of the g operation was not affected. Safety depended on the environmental direction, with more stable operation possible if the heading-control function of FLBT is applied to avoid beam-sea conditions.

• Applied Chemistry for Engineering
• /
• v.22 no.2
• /
• pp.133-137
• /
• 2011

In this study, illite was size-reduced using a wet-ball-milling treatment to improve its dispersion. Changes in illite particle size, size distribution, and dispersion characteristics after varying the treatment period were investigated. And the dispersion and dispersion stability of illite solution after 2 h wet ball milling treatment with different pH conditions were also evaluated. The illite particle size significantly decreased as the treatment time increased and the size reduction effect of wet ball milling deteriorated above 2 h treatment time. In addition, illite particle size was more evenly distributed as the treatment time increased. X-ray diffraction (XRD) analysis showed that no crystal structural changes of illite were induced, but the characteristic peak of illite the weaker due to the size reduction and exfoliation, as the treatment time increased. Zeta potential analysis showed that the illite dispersion improved, as the treatment time increased. The illite wet-ball-mill treated at pH 2 had the lowest dispersion stability. Illite dispersion and dispersion stability increased as pH increased, due to the increase in surface ionization. Hence, the results showed that as the treatment time increased, the illite particle size decreased, and dispersion and dispersion stability improved due to the increase in surface energy and repulsion force between particles.

• The Journal of Korean Philosophical History
• /
• no.54
• /
• pp.77-113
• /
• 2017

In late Chosen(朝鮮), the concept of illustrious virtue(明德) became an important issue of debate. However, previous studies did not focus on how the concept emerged as an issue. This paper aimed to explore the problem, and for this purpose, paid attention to Horak(湖洛) debate. Oiam(巍巖) Yi Gan(李柬), in the course of discussion with Namdang(南塘), finally argued that mind(心) clearly distinguishes from temperament(氣質). The goals of the claim were to clearly divide mind and temperament, and to emphasize mind's control of temperament. Through this, he wanted to reject the possibility of being affected by temperament in aroused state(未發). And he presented the concept of illustrious virtue as a critical evidence supporting his argument. He argued that because mind is same with illustrious virtue, it has a special status that essentially distinguished from the temperament, even if both mind and temperament are all material force(氣). This argument led to new discussion trend in the debate. it was to form a definition of the mind, based on defining the relationship between spiritual perception(虛靈知覺), temperament and illustrious virtue. The trend was reflected in the debate on 'Whether illustrious virtue is the same for everyone or varies from person to person(明德分殊)'. Through the process of analysis in this paper, we could detect a tendency that definition of mind has become an independent subject.

• The Journal of Korean Philosophical History
• /
• no.41
• /
• pp.9-38
• /
• 2014

Hanhweon-dang Kim Goeng-pil(1454~1504) sublimated ethics whose lead was opened up by Jeong Mong-ju in late Goryeo as one scholarly tendency. Kim Goeng-pil was called 'the father of ethics in Joseon' and has been respected as a model of ethicist for 400 years since then. Following Kim Goeng-pil, Confucian scholars of Joseon cultivated perseverance through Xiaoxue and the perseverance was sublimated to Confucian scholars' energy and then that of state, which served as driving force to keep the national legacy. Kim Goeng-pil suggested how to study with Xiaoxue and sought moral human beings and ethically ideal societies based on strong practicability which is required in Xiaoxue. Individuals' cultivation and social reform are not at a different dimension. Spirit of 'self-cultivation' that Kim Goeng-pil himself demonstrated advanced to pursuit of ethical, ideal state when reaching a level of Jo Kwang-jo. Kim Goeng-pil thought that teaching in Xiaoxue could be achieved through 'Gyeong (敬, respect).' It is the key of Neo-Confucianism in Joseon to control one's mind through the cultivating method of 'Gyeong.' Kim Goeng-pil settled Joseon's Confucianism as 'practical ethics(心學).' Before Kim Goeng-pil, no scholars had well presented the aspects of practical ethics. After King Myeongjong and Seonjo, Confucianism in Joseon worked as the cornerstone of practical ethics. Since mid-17th century, the system of practical ethics had been firmly established with focus on 'Gyeong. Literary men of Kim Goeng-pil and scholars they fostered led the academic and political world of Joseon after mid-16th century. They played the lead in Sarim faction's(士林派) ruling after King Seonjo came to throne. The very foundation which sublimated Joseon to the ethically ideal state and made the Dynasty a 'state of Sarim' was actually laid by Kim Goeng-pil.

• Ecology and Resilient Infrastructure
• /
• v.10 no.3
• /
• pp.51-63
• /
• 2023

Riverine tree management is crucial in realizing a balance between flood control and ecological preservation, which requires an accurate assessment of the impact of trees on river water elevations. In this study, eight different formulas for evaluating vegetation roughness considering the drag force acting on trees, were reviewed, and the characteristics and applicability of these methods were evaluated from a practical engineering perspective. The study compared the characteristics of vegetation roughness measurement methods for calculated roughness coefficients at different water depths and analyzed factors such as effects of tree canopy width, tree density and diameter, and tree stiffness coefficient, and water level estimation results. A comparison of roughness coefficients at the same water depths revealed that the Kouwen and Fathi-Moghadam formulas and the Fischenich formula yield excessive drag coefficients compared to other formulas. Factors such as channel geometry, tree diameter, and tree density showed varying trends depending on the formula but did not exhibit excessive outliers. Formulas considering the tree stiffness coefficient, such as the Freeman et al.'s formula and the Whittaker et al.'s formula, showed significant variations in drag coefficients depending on the stiffness coefficient. When applied to small- and medium-sized virtual rivers in South Korea using the drag coefficient results from the eight formulas, the results indicated a maximum increase in water level of approximately 0.2 to 0.4 meters. Based on this review, it was concluded that the Baptist et al., Huthoff et al., Cheng, Luhar, and Nepf's formulas, which exhibit similar characteristics and low input data uncertainties, are suitable for practical engineering applications.

• Steel and Composite Structures
• /
• v.47 no.1
• /
• pp.91-102
• /
• 2023

To study the evaluation standard and control limit of mortar filling layer void length, in this paper, the train sub-model was developed by MATLAB and the track-bridge sub-model considering the mortar filling layer void was established by ANSYS. The two sub-models were assembled into a train-track-bridge coupling dynamic model through the wheel-rail contact relationship, and the validity was corroborated by the coupling dynamic model with the literature model. Considering the randomness of fastening stiffness, mortar elastic modulus, length of mortar filling layer void, and pier settlement, the test points were designed by the Box-Behnken method based on Design-Expert software. The coupled dynamic model was calculated, and the support vector regression (SVR) nonlinear mapping model of the wheel-rail system was established. The learning, prediction, and verification were carried out. Finally, the reliable probability of the amplification coefficient distribution of the response index of the train and structure in different ranges was obtained based on the SVR nonlinear mapping model and Latin hypercube sampling method. The limit of the length of the mortar filling layer void was, thus, obtained. The results show that the SVR nonlinear mapping model developed in this paper has a high fitting accuracy of 0.993, and the computational efficiency is significantly improved by 99.86%. It can be used to calculate the dynamic response of the wheel-rail system. The length of the mortar filling layer void significantly affects the wheel-rail vertical force, wheel weight load reduction ratio, rail vertical displacement, and track plate vertical displacement. The dynamic response of the track structure has a more significant effect on the limit value of the length of the mortar filling layer void than the dynamic response of the vehicle, and the rail vertical displacement is the most obvious. At 250 km/h - 350 km/h train running speed, the limit values of grade I, II, and III of the lengths of the mortar filling layer void are 3.932 m, 4.337 m, and 4.766 m, respectively. The results can provide some reference for the long-term service performance reliability of the ballastless track-bridge system of HRS.

• Korean Journal of Legislative Studies
• /
• v.25 no.2
• /
• pp.5-33
• /
• 2019

This study aims to explore the implications of the 2019 European Parliament elections. Existing studies show that European elections serve as secondary elections dominated by domestic issues. However, the 2019 European elections have highlighted pan-European issues such as the Brexit negotiations and the rise of far-right populism, with voter turnout also rising sharply to 50.62%, which is the highest record since the 2000s. There was also a significant change in the number of parliamentary seats held by each political group. First, the European People's Party(EPP) and the Progressive Alliance of Socialists and Democrats(S&D), which had hitherto led the European Parliament, failed to achieve a majority. Second, the number of seats won by Renew Europe, a new liberal-centrist group, was considerably high. Third, the far-right groups organized a full-fledged political force by rallying around the Identity and Democracy(ID) group. The rise of liberal-centrism can be explained as a reaction to the popularity of anti-European populism. Renew Europe's emphasis on open-market competition has created a different issue, especially since the center-left and center-right groups have stressed on the need for state intervention in employment, welfare, security and immigration control. Along with far-right populism, liberal centrism has also reshuffled Europe's political cleavage, and the conflict between 'liberalism' and 'protectionism' has become more evident in the European Parliament.