• Title/Summary/Keyword: 변화

Search Result 122,658, Processing Time 0.174 seconds

Psychiatric Manifestations of Anti-NMDA Receptor Encephalitis: A Case Report (항-NMDA 수용체 뇌염의 정신증상: 증례보고)

  • Kim, Hyunseuk;Lee, Haeyoung;Lee, Sang-Shin
    • Korean Journal of Psychosomatic Medicine
    • /
    • v.29 no.2
    • /
    • pp.207-212
    • /
    • 2021
  • Anti-N-methyl-D-aspartate receptor (Anti-NMDAR) encephalitis is a neuroinflammatory disease mediated by autoantibodies to NMDAR. In the initial clinical stages of anti-NMDAR encephalitis, psychiatric symptoms like delusions, perceptual disturbances, and disorganized speech or behaviors are pronounced even without obvious neurological symptoms. Early treatments like immunotherapy and/or tumor removal are central to good clinical outcomes. Hence, it is important to diagnose early anti-NMDAR encephalitis, distinguishing it from mental disorder. In the present case study, the authors described psychiatric symptoms assessed with Positive and Negative Syndrome Scale (PANSS) of Ms. A, a 26-year-old woman, in the early phase of anti-NMDAR encephalitis. We will discuss the characteristic psychopathology of anti-NMDAR encephalitis toward prompt diagnosis and treatment. Ms. A showed a higher negative subscale score than positive one on the PANSS. Compared with mental disorder, negative symptoms and cognitive impairment would be more prominent in the early stage of anti-NMDAR encephalitis. Rituximab and teratoma removal were effective, and quetiapine showed good tolerability. It is recommended to evaluate anti-NMDAR encephalitis when negative symptoms, cognitive impairment, catatonia, changes in consciousness level, and neurological symptoms are observed, especially in young women.

Performance Characteristics of No-Fines Polymer Concrete using Recycled Coarse Aggregate with Binder Contents (결합재의 함량에 따른 순환굵은골재 사용 무세골재 폴리머 콘크리트의 성능 발현 특성)

  • Kim, Do-Heon;Jung, Hyuk-Sang;Kim, Dong-Hyun
    • Journal of the Korean Recycled Construction Resources Institute
    • /
    • v.9 no.4
    • /
    • pp.433-442
    • /
    • 2021
  • In this study, the properties of no-fines polymer concrete with different polymer binder contents were evaluated. The polymer concrete was formulated using a polymeric binder (unsaturated polyester resin), fly ash, and recycled coarse aggregate (60%) and crushed coarse aggregate (40%). The polymeric binder content (4.0-6.0wt.%) was used as an experimental variable because it dramatically affects both the cost-effectiveness and material properties. The results showed that the density, compressive strength, flexural strength both before and after exposure to freezing and thawing increased as the polymer binder content increased, while the absorption, void ratio, permeable voids, coefficient of permeability, and acid resistance (mass loss by acid attack) decreased as the polymeric binder content increased. In particular, even though the void ratio was 18.4% and the water permeability coefficient was 7.3mm/sec, the compressive strength and flexural strength were as high as 38.0MPa and 10.0MPa, respectively, much more significant than those of previous studies. Other properties such as absorption and acid resistance were also found to be excellent. The results appear to be rooted in the increased adhesion of the binder by adding a cross-linking agent and the surface hydrophobicity of the polymer.

The Impact of Capital Structure for Ship Investments on Corporate Stability (선박투자자금의 조달구조가 기업의 안정성에 미치는 영향)

  • Cho, Seong-Soon;Yun, Heesung
    • Journal of Navigation and Port Research
    • /
    • v.45 no.6
    • /
    • pp.276-283
    • /
    • 2021
  • The capital structure of the shipping business, which is characterized by its capital intensity and extreme market volatility, is closely related to long-term stability. Research in this area has been conducted mostly in the form of deriving the determinants of capital structure from company-wise financial ratios. This research, on the other hand, has a different approach to the topic. It identifies the relationship between actual cash profit and loss and other variables - i.e. actual vessel prices, interest rates and leverage ratio - by employing historical simulation. The result demonstrates that the P anamax cash profit shows 0 (break-even point) when the debt weight reaches 64.38% (debt ratio 180.74%) and the Cape, 73.04% (debt ratio 270.92%). Additionally, the ships of different types show a divided pattern for the pre- and post-'Super Boom'. It indicates that the business area and the market cycle should be considered when a leverage strategy is established. This research benefits shipping companies set a rational leverage strategy as well as delivers a reasonable guideline to government authorities for the development of a sound policy on shipping finance.

Control of Bending Behavior of Simple Beams Using CTMD (CTMD의 질량비에 따른 단순보의 휨거동 제어효과)

  • Heo, Gwang-Hee;Seo, Sang-Gu;Kim, Chung-Gil;Jeon, Seung-Gon;Kim, Min-Ki
    • Journal of the Korea institute for structural maintenance and inspection
    • /
    • v.25 no.6
    • /
    • pp.12-18
    • /
    • 2021
  • The purpose of this study is to effectively mitigate the bending displacement that occurs in the bridge due to forced vibration. We developed CTMD (Combine Tuned Mass Damper) that combines the relationship between spring and mass to control the bending behavior of simple beams. The experiment was conducted to confirm the control effect according to the change in the mass ratio of the developed CTMD. The developed CTMD is designed and manufactured so that the mass ratio can be adjusted according to the characteristics of the bridge. The maximum load of the spring applied to CTMD was fixed at 33.15 N. In order to evaluate the performance of the developed CTMD, a simple beam composed of hinges and rollers as boundary conditions was fabricated. In the experimental method, a CTMD was installed in the center of a simple beam and the deflection displacement according to the mass ratio was measured. The shaking condition was shaken at 3 Hz to induce the maximum bending behavior of the simple beam. As a result of the experiment, it was confirmed that when the optimal mass ratio was 2.1, the damping rate of the bending behavior displacement was about 71.2 %, indicating the best control effect.

Compressive and Flexural Properties of Concrete Reinforced with High-strength Hooked-end Steel Fibers (고강도 후크형 강섬유로 보강된 콘크리트의 압축 및 휨 성능)

  • Wang, Qi;Kim, Dong-Hwi;Yun, Hyun-Do;Jang, Seok-Joon;Kim, Sun-Woo
    • Journal of the Korea institute for structural maintenance and inspection
    • /
    • v.25 no.6
    • /
    • pp.209-217
    • /
    • 2021
  • This paper investigates the effect of high strength hooked-end steel fiber content and aspect ratio on the compressive and flexural performance of concrete. A total of ten mixtures were prepared and tested. Concretes with specific compressive strength of 30 MPa were reinforced with three different aspect ratios (l/d) of steel fibers 64, 67, and 80 and three different percentages of steel fibers 0.25, 0.50, and 0.75% by volume of concrete. Tensile strengths of steel fibers with l/d of 64, 67, and 80 are 2,000, 2,400, and 2,100 MPa, respectively. The compressive and flexural properties of plain and steel fiber-reinforced concrete (SFRC) mixtures were evaluated and compared. The experimental results indicated that the incorporation of high-strength hooked-end steel fibers had significant effects on the compressive and flexural performance of concrete. With the increase of steel fiber content, compressive performances, such as Poisson's ratio and toughness, of concrete were improved. The steel fibers with the least l/d of 67 resulted in a larger enhancement of compressive performances. The residual flexural strength, that is, post-cracking flexural resistance and toughness, of concrete is mainly depended on the dosage and aspect ratio of steel fibers. The residual flexural strength at serviceability (SLS) and ultimate limit state (ULS) defined in fib Model Code 2010 (MC2010) is increased as the fiber content and aspect ratio increase.

Identification of Failure Cause for Elastomeric Bearing in Bridge by Earthquakes (지진에 의한 교량의 탄성받침장치 손상 원인 규명)

  • Seo, Young-Deuk;Choi, Hyoung-Suk;Kim, In-Tae;Kim, Jung Han;Jeong, Young-Soo
    • Journal of the Korea institute for structural maintenance and inspection
    • /
    • v.25 no.6
    • /
    • pp.19-26
    • /
    • 2021
  • The seismic isolation system have been applied in order to protect the collapse of bridge by seismic load and the vertical load transmitted from the superstructure. However, the failure and damages of non-shrinkage mortar, isolator and wedge in total 12 bridge were reported by Pohang Earthquake. In this study, the damage mechanism and behavior characteristics of elastomeric bearing by an earthquake were evaluated to consider the seismic isolation system including non-shrinkage mortar and the seat concrete of pier. To discuss the effect of installed wedge and damage mode of elastomeric bearing, the compressive-shear tests were carried out. Also, the mechanical behaviors and damage mechanism for each component of elastomeric bearing were evaluated by using finite element analysis. From the test results, the cracks were created at boundary between non-shrinkage mortar and seismic isolator and the shear loads were rapidly increased after bump into wedge. The cause for damage mechanism of seismic isolation system was investigated by comparing stress distribution of anchor socket and non-shrinkage mortar depending on wedge during earthquake.

FEA Simulations on Water Absorption in Various Pre-Cracked Concretes (유한요소해석에 기반한 콘크리트 균열 조건에 따른 수분흡수 현상 분석)

  • Kim, Kun-Soo;Park, Ki-Tae;Kim, Jaehwan
    • Journal of the Korea institute for structural maintenance and inspection
    • /
    • v.25 no.5
    • /
    • pp.68-75
    • /
    • 2021
  • This study performed simulating water absorption in various pre-cracked concretes. 2D-Finite Element Analysis (2D-FEA) model was developed based on experimental results on the amount of absorbed water in concrete with the exposure time. Results from the 2D-FEA showed that both crack width and crack depth strongly affect the amount of absorbed water in cracked concrete. In addition, water absorption rate is introduced and a predictive equation is suggested to estimate the rate in order to quantify the amount of absorbed water in cracked concrete. It was confirmed that water absorption in concrete having less than 150 mm crack depth was dominated as a main transport factor regardless of crack width. Therefore, considering that steel corrosion caused by chlorides dissolved in water mainly occurs in reinforced concrete structures, it is necessary that crack depth as well as crack width should be investigated in reinforced concrete structures at the time of field-inspection.

A Study on the Evaluation Method to Flexural-bonding Behavior of FRP-Rebar Concrete Member (FRP를 보강근으로 사용한 콘크리트 부재의 휨-부착 거동 평가방법에 관한 연구)

  • Choi, So-Yoeng;Choi, Myoung-Sung;Kim, Il-Sun;Yang, Eun-Ik
    • Journal of the Korea institute for structural maintenance and inspection
    • /
    • v.25 no.5
    • /
    • pp.149-156
    • /
    • 2021
  • FRP has been proposed to replace the steel as a reinforcement in the concrete structures for addressing the corrosion issue. However, FRP-Rebar does not behave in the same manner as steel because the properties of FRP are different. For example, FRP-Rebar has a high tensile strength, low stiffness, and linear elastic behavior which results in a difference bonding mechanism to transfer the load between the reinforcement and the surrounding concrete. Therefore, bonding behavior between FRP-Rebar and concrete has to be investigated using the bonding test. So, Pull-out test has been used to estimate bond behavior because it is simple. However, the results of pull-out test have a difference with flexural-boding behavior of FRP-Rebar concrete member. So, it is needed to evaluate the real fleuxral-bonding behavior. In this study, the evaluation method to flexural-bonding behavior of FRP-Rebar concrete member was reviewed and compared. It was found that the most accurate evaluation method for the fleuxral-bonding behavior of FRP-Rebar concrete member was splice beam test, however, the size and length of specimen have to increase than other test method and the design and analysis of splice beam is complex. Meanwhile, characteristics of concrete could be reflected by using arched beam test, unlike hinged beam test which is based on the ignored change of moment arm length in equilibrium equation. However, the possibility of shear failure exists before the flexural-bonding failure occur.

Study on the Production Process of Performance Arts Visualization Projects: Focused on a Case Analysis of NT Live Cinema Broadcasts (공연예술 영상화 제작과정 연구:NT Live 시네마 브로드캐스트 사례분석을 중심으로)

  • Park, Jin-Won;Kim, Ga-eun
    • The Journal of the Korea Contents Association
    • /
    • v.21 no.7
    • /
    • pp.45-58
    • /
    • 2021
  • This study aims to select representative performance art visualization projects that react to changes in the culture enjoyment methods and needs of contemporary performance art consumers for performance art culture value creation and vitalization that suit the Fourth Industry and a global age, verify new cultural value creation possibilities of performance projects, and look into important matters and keynotes of production processes. Focusing on the report 'NT Live-Digital broadcast of theatre Learning from the pilot season'(2011), a thorough analysis was conducted on the Royal National Theatre of England, a leading model of cinema broadcast performance visualization projects, including the purpose, production processes (copyright agreements, personnel compositions, filming and broadcasting), marketing methods, and audiences of its "NT Live" project and observations were made of production processes and cultural and artistic values that differ from existing performance art to examine administrative and financial keynotes for the sustainability of performance visualization projects. Through this, possibilities of source creations with artistic, cultural, and economic values that cinema broadcast (live performance broadcast) performance viewing methods have as a new form of performance art products can be verified. In addition, the development of various performance approaches that respond to the culture enjoyment methods and consumption patterns of audiences will result in the vitalization of performing arts visualization projects through the enhancement of popular appeal and the expansion of audience types of the performing arts field.

Changes in Visual Response Speed, Functional Movement, Body Balance, and Lung Capacity after a 10-Week Body Stability Exercise Program for High School Male Handball Players (10주간의 고교 남자 핸드볼 선수 신체 안정화 프로그램 후 시각 반응 속도, 기능적 움직임, 신체 균형, 폐활량 변화)

  • Kang, Yang-Hoon;Kim, Chul-Seung
    • The Journal of the Korea Contents Association
    • /
    • v.21 no.7
    • /
    • pp.637-649
    • /
    • 2021
  • This study aims to see, a 10-weeks program of Body Stability Exercise(BSE) was conducted on 21 male handball players at Muan Y High School and then, the results of changes in Visual Response Speed Test, Functional Movement Screen, Y-Balance Test, and Vital Capacity were observed, compared and analyzed to provide follow-up management and training data that can be used to reduce injuries and improve performance. After training, strength and quickness were increased significantly and reaction time was significantly shortened (p<0.001). The total score of Functional Movement Screen was increased from 10.43±1.16, before training to 12.05±1.07 after training, which was statistically significant(p<0.001). Y-Balance Test was significantly increased from 89.18±6.99 before training to 91.39±7.33 after training(p<0.001). The Vital Capacity increase was also shown to be more than statistically significant(p<0.001). The 10-week BSE program improved speed, agility, Functional Movement Screen, Y-Balance Test, and Vital Capacity. In conclusion, it's can prevent or reduce injuries and performance could be improved while playing handball.