• Title/Summary/Keyword: Reflected pressure

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Clinical Practice Guidelines for the Medical and Surgical Management of Primary Intracerebral Hemorrhage in Korea

  • Kim, Jeong Eun;Ko, Sang-Bae;Kang, Hyun-Seung;Seo, Dae-Hee;Park, Sukh-Que;Sheen, Seung Hun;Park, Hyun Sun;Kang, Sung Don;Kim, Jae Min;Oh, Chang Wan;Hong, Keun-Sik;Yu, Kyung-Ho;Heo, Ji Hoe;Kwon, Sun-Uck;Bae, Hee-Joon;Lee, Byung-Chul;Yoon, Byung-Woo;Park, In Sung;Rha, Joung-Ho
    • Journal of Korean Neurosurgical Society
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    • v.56 no.3
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    • pp.175-187
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    • 2014
  • The purpose of this clinical practice guideline (CPG) is to provide current and comprehensive recommendations for the medical and surgical management of primary intracerebral hemorrhage (ICH). Since the release of the first Korean CPGs for stroke, evidence has been accumulated in the management of ICH, such as intracranial pressure control and minimally invasive surgery, and it needs to be reflected in the updated version. The Quality Control Committee at the Korean Society of cerebrovascular Surgeons and the Writing Group at the Clinical Research Center for Stroke (CRCS) systematically reviewed relevant literature and major published guidelines between June 2007 and June 2013. Based on the published evidence, recommendations were synthesized, and the level of evidence and the grade of the recommendation were determined using the methods adapted from CRCS. A draft guideline was scrutinized by expert peer reviewers and also discussed at an expert consensus meeting until final agreement was achieved. CPGs based on scientific evidence are presented for the medical and surgical management of patients presenting with primary ICH. This CPG describes the current pertinent recommendations and suggests Korean recommendations for the medical and surgical management of a patient with primary ICH.

Uncoupled Solution Approach for treating Fluid-Structure Interaction due to the Near-field Underwater Explosion (근거리 수중폭발에 따른 유체-구조 상호작용 취급을 위한 비연성 해석방법)

  • Park, Jin-Won
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.20 no.10
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    • pp.125-132
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    • 2019
  • Because the water exposed to shock waves caused by an underwater explosion cannot withstand the appreciable tension induced by the change in both pressure and velocity, the surrounding water is cavitated. This cavitating water changes the transferring circumstance of the shock loading. Three phenomena contribute to hull-plate damage; initial shock loading and its interaction with the hull plate, local cavitation, and local cavitation closure then shock reloading. Because the main concern of this paper is local cavitation due to a near-field underwater explosion, the water surface and the waves reflected from the sea bottom were not considered. A set of governing equations for the structure and the fluid were derived. A simple one-dimensional infinite plate problem was considered to verify this uncoupled solution approach compared with the analytic solution, which is well known in this area of interest. The uncoupled solution approach herein would be useful for obtaining a relatively high level of accuracy despite its simplicity and high computational efficiency compared to the conventional coupled method. This paper will help improve the understanding of fluid-structure interaction phenomena and provide a schematic explanation of the practical problem.

A review of gender discourse in the Ghibli animation "The Tale of the Princess Kaguya" (지브리 애니메이션 <가구야 공주 이야기>에서 나타나는 젠더 담론에 대한 고찰)

  • Kim, Ye-Eun;Kim, Soong-Hyun
    • Journal of Digital Convergence
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    • v.19 no.9
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    • pp.289-297
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    • 2021
  • Animation is a media reflecting social ideas, not only conveying information but also creating a new discourse. The purpose of this paper is to examine the social issues and gender discourse reflected in the media by analyzing the gender discourse inherent in the protagonist and surrounding characters, narrative characteristics, and background of the Ghibli animation "The Tale of the Princess Kaguya". As a research method for this purpose, figure out social problems related to gender performance, and analyze prior researches to derive a connection with the gender discourse in the animation. Grandfather is symbolic of a father who forces his daughter to follow his chosen happiness, and grandmother represents a mother who can not stop her husband. Stemaru is the character not in the original, posing a question of the problem of gender performance while failing to get married due to lack of sufficient wealth and honor. Princess Kaguya had been self-reliant and active like a modern woman at the beginning of the story. However, after being suppressed by society and people around her, the stereotyped gender performance forced Kaguya, who longed for the earth, to wish to return to the moon. Such social pressure happens in modern society. Gender performance is a systemic problem to be solved with systemic change. For this reason, constant consideration such as this paper is needed.

Hemodynamic, Autonomic, and Vascular Function Changes after Sleep Deprivation for 24, 28, and 32 Hours in Healthy Men

  • Slomko, Joanna;Zawadka-Kunikowska, Monika;Kozakiewicz, Mariusz;Klawe, Jacek J.;Tafil-Klawe, Malgorzata;Newton, Julia L.;Zalewski, Pawel
    • Yonsei Medical Journal
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    • v.59 no.9
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    • pp.1138-1142
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    • 2018
  • This study aimed to analyze the impact of sleep deprivation (SD) on cardiac, hemodynamic, and endothelial parameters and to determine whether these are sustained with increased periods of SD. The study included 60 healthy men (mean: age $31.2{\pm}6.3years$; body mass index $24.6{\pm}2.6kg/m^2$). Hemodynamic parameters, parameters of myocardial contractility, spectral analysis of heart rate (HR) and blood pressure (BP) variability, and the sensitivity of arterial baroreflex function were evaluated. Biochemical tests were performed to assess L-arginine (L-Arg) and asymmetric dimethylarginine (ADMA) levels in reflection of endothelial nitric oxide synthase ability. Measurements of cardiovascular system parameters were obtained at 9 a.m. (baseline) on the first day of the study and 9 a.m. (24-h SD), 1 p.m. (28-h SD), and 5 p.m. (32-h SD) on the second day. Blood samples for evaluating biochemical parameters were obtained at baseline and after 24-h SD. ANOVA Friedman's test revealed a significant effect for time in relation to HR (${\chi}^2=26.04$, df=5, p=0.000), systolic BP (${\chi}^2=35.98$, df=5, p=0.000), diastolic BP (${\chi}^2=18.01$, df=5, p=0.003), and mean BP (${\chi}^2=28.32$, df=5, p=0.000). L-Arg and ADMA levels changed from $78.2{\pm}12.9$ and $0.3{\pm}0.1$ at baseline to $68.8{\pm}10.2$ and $0.4{\pm}0.1$ after 24-hr SD, respectively (p=0.001, p=0.004). SD in healthy men is associated with increases in BP, which appear to occur after 24 hours of SD and are maintained over increasing periods of SD. The observed hemodynamic changes may have resulted due to disordered vascular endothelial function, as reflected in alterations in L-Arg and ADMA levels.

Numerical study on basal heave stability of a circular vertical shaft constructed in clay (연약 점성토 지반에 시공되는 원형 수직구의 히빙 안정성에 대한 수치해석적 연구)

  • Kang, Seok-Jun;Cho, Gye-Chun
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.24 no.3
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    • pp.231-245
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    • 2022
  • When vertical shafts are constructed in soft clay with low strength, there is a risk of basal heave, which causes the excavation surface to heave due to the low bearing capacity of the ground against the imbalance of earth pressure at the excavation surface. Methods of deriving a safety factor have been proposed to evaluate the stability against the basal heave. However, there are limitations in that it is difficult to accurately evaluate the heave stability because many assumptions are included in the theoretical derivation. In this study, assuming that a circular vertical shaft is constructed in soft clay, the existing safety factor equation proposed through a theoretical approach was supplemented. Bearing capacity according to the shaft geometry, inhomogeneity of the soil, and the effect of soil plug were considered theoretically and applied in a previous safety factor equation. A three-dimensional numerical analysis was conducted to simulate the occurrence of basal heave and review the supplemented equation through various case studies. Several series of case studies were conducted targeting various factors affecting heave stability. It was verified that the additionally considered characteristics were properly reflected in the supplemented equation. Furthermore, the effects of each factor constituting the safety factor equation were examined using the results of the numerical analysis performed by simulating various cases. It was confirmed that considering the undrained shear strength increment according to depth had the most significant effect on the calculation of the safety factor.

Correlation and Spatial Analysis between the number of Confirmed Cases of the COVID-19 and Traffic Volume based on Taxi Movement Data (택시 이동 데이터 기반 COVID-19 확진자 수와 교통량 간의 상관관계 및 공간분석)

  • Jeon, Seung Bae;Kim, Geon;Jeong, Myeong-hun
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.39 no.6
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    • pp.609-618
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    • 2021
  • The spread and damage of COVID-19 are putting significant pressure on the world, including Korea. Most countries place restrictions on movement and gathering to minimize contact between citizens and these policies have brought new changes to social patterns. This study generated traffic volume data on the scale of a road network using taxi movement data collected in the early stages of the COVID-19 third pandemic to analyze the impact of COVID-19 on movement patterns. After that, correlation analysis was performed with the data of confirmed cases in Daegu Metropolitan City and Local Moran's I was applied to analyze the effect of spatial characteristics. As a result, in terms of the overall road network, the number of confirmed cases showed a negative correlation with taxi driving and at least -0.615. It was confirmed that citizens' movement anxiety was reflected as the number of confirmed cases increased. The commercial and industrial areas in the center of the city confirmed the cold spot with a negative correlation and low-low local Mona's I. However, the road network around medical institutions such as hospitals and spaces with spatial characteristics such as residential complexes was high-high. In the future, this analysis could be used for preventive measures for policymakers due to COVID-19.

Effect of Stress History on CPT-DMT Correlations in Granular Soil (응력이력이 사질토의 CPT-DMT 상관관계에 미치는 영향)

  • Lee, Moon-Joo;Choi, Sung-Kun;Kim, Min-Tae;Lee, Ju-Hyeong;Lee, Woo-Jin
    • Journal of the Korean Geotechnical Society
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    • v.26 no.7
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    • pp.7-16
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    • 2010
  • Stress history increases the residual horizontal stress of granular soil and, consequently, the penetration resistance. This study analyzes the effect of stress history on the cone resistance ($q_c$), horizontal stress index ($K_D$) and dilatometer modulus ($E_D$) of CPT and DMT from calibration chamber specimen in OC as well as NC state. Test results show that the normalized cone resistance by mean effective stress correlates well with the relative density and the state parameter, whereas the normalized cone resistance by vertical effective stress is a little affected by stress history. The influence of stress history is more reflected on $K_D$ than $E_D$ and $q_c$. The $K_D/K_0$, in which the effect of stress history on $K_D$ is compensated by the at-rest coefficient of earth pressure, $K_0$, is related to relative density, state parameter and the normalized cone resistance by mean effective stress. It is also observed that the normalized dilatometer modulus by mean effective stress ($E_D/{\sigma}_m'$) shows a unique correlation with the state parameter, regardless of stress history.

Regenerating Condition Optimization of NGCC Combined Carbon Capture Process Simultaneously Considering Absorption and Regeneration Rates (흡수율과 재생율을 동시 고려한 천연가스복합발전 공정 연계 이산화탄소 포집 공정의 재생 조건 최적화)

  • Jeong Hun Choi;Young-Hwan Chu
    • Korean Chemical Engineering Research
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    • v.61 no.3
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    • pp.368-377
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    • 2023
  • Natural Gas Combined Cycle(NGCC) recently receives lots of attention as an attractive form of power plants by virtue of its low carbon emission compared with coal-fired power plant. Nevertheless, it also needs carbon capture process since it is difficult to completely suppress carbon emission even for the NGCC. A simulation study has been performed to optimize operating condition of a carbon capture process using MEA considering low partial pressure of carbon dioxide in NGCC emission gas. For accurate optimization, overall process model including both NGCC and the carbon capture process has been built with a simulation software. Then, optimization in which various performance indices such as carbon dioxide absorption rate, solvent regeneration rate and power loss in the NGCC are simultaneously reflected has been done. Especially, it is noticeable that this study focuses on not only the amount of energy consumption but also the absorption and regeneration performance of carbon capture process. The best result considering all the performance indices has been achieved when the reboiler temperature is 120 ℃ and the reason has been analyzed.

Ecological Connectivity and Network Analysis of the Urban Center in a Metropolitan City (대도시 도심의 생태적 연결성 및 연결망 분석)

  • Jaegyu Cha
    • Journal of Environmental Impact Assessment
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    • v.32 no.6
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    • pp.503-515
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    • 2023
  • The disconnection and fragmentation of ecological spaces that occur during the development process pose a significant threat to biodiversity. Urban center areas with high development pressure are particularly susceptible to low connectivity due to a scarcity of ecological space. This issue tends to be more pronounced in larger cities.To address this challenge, continuous efforts are needed to assess and improve the current state of ecological space connectivity at the level of individual projects and urban management. However, there is a lack of discussion regarding the analysis and improvement of ecological connectivity in metropolitan cities In line with this objective, this study evaluated the connectivity of ecological spaces in the city centers of Seoul, Busan, Daegu, Incheon, Gwangju, Daejeon, and Ulsan. The evaluation revealed that city centers exhibited lower connectivity of ecological spaces compared to their peripheries or the overall city. In addition, in the ecological network analysis that reflected regional characteristics, such as the species distribution model conducted on Daejeon, 510 optimal paths connecting forests of more than 1ha were derived. This study is significant as an example of deriving an ecological network based on regional characteristics, including quantitative figures necessary for establishing goals to improve urban ecological connectivity and biodiversity. It is anticipated that the results can be utilized to propose directions for enhancing ecological connectivity in environmental impact assessments or urban management and to establish an evaluation framework.

Analysis of Hydrodynamics in a Directly-Irradiated Fluidized Bed Solar Receiver Using CPFD Simulation (CPFD를 이용한 태양열 유동층 흡열기의 수력학적 특성 해석)

  • Kim, Suyoung;Won, Geunhye;Lee, Min Ji;Kim, Sung Won
    • Korean Chemical Engineering Research
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    • v.60 no.4
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    • pp.535-543
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    • 2022
  • A CPFD (Computational particle fluid dynamics) model of solar fluidized bed receiver of silicon carbide (SiC: average dp=123 ㎛) particles was established, and the model was verified by comparing the simulation and experimental results to analyze the effect of particle behavior on the performance of the receiver. The relationship between the heat-absorbing performance and the particles behavior in the receiver was analyzed by simulating their behavior near bed surface, which is difficult to access experimentally. The CPFD simulation results showed good agreement with the experimental values on the solids holdup and its standard deviation under experimental condition in bed and freeboard regions. The local solid holdups near the bed surface, where particles primarily absorb solar heat energy and transfer it to the inside of the bed, showed a non-uniform distribution with a relatively low value at the center related with the bubble behavior in the bed. The local solid holdup increased the axial and radial non-uniformity in the freeboard region with the gas velocity, which explains well that the increase in the RSD (Relative standard deviation) of pressure drop across the freeboard region is responsible for the loss of solar energy reflected by the entrained particles in the particle receiver. The simulation results of local gas and particle velocities with gas velocity confirmed that the local particle behavior in the fluidized bed are closely related to the bubble behavior characterized by the properties of the Geldart B particles. The temperature difference of the fluidizing gas passing through the receiver per irradiance (∆T/IDNI) was highly correlated with the RSD of the pressure drop across the bed surface and the freeboard regions. The CPFD simulation results can be used to improve the performance of the particle receiver through local particle behavior analysis.