• Title/Summary/Keyword: 복부

Search Result 2,091, Processing Time 0.036 seconds

Effects of Corrugated Webs on the Ultimate Behavior of Horizontally Curved I-shaped Girders (파형 복부판이 수평 곡선 I형 거더의 극한 거동에 미치는 영향)

  • Kim, Seungjun;Han, Taek Hee;Won, Deok Hee;Kang, Young Jong
    • KSCE Journal of Civil and Environmental Engineering Research
    • /
    • v.33 no.4
    • /
    • pp.1327-1336
    • /
    • 2013
  • In this study, the effects of corrugated webs on the ultimate behavior of horizontally curved I-shaped girders are investigated. Because of the geometric characteristics of corrugated plates, corrugated webs can be used for enhancing torsional and warping stiffness of plate girders. Many researches have been conducted to study the effects of corrugated webs on the ultimate behavior of straight girders. But, the studies of the ultimate behavior of horizontally curved girders with corrugated webs, which generally show out-of plane behavior manly, have been rarely performed so far. By performing inelastic-nonlinear analysis, the ultimate behavior of curved girders with corrugated webs is studied in this paper. Laterally unsupported length and subtended angle of girders, and length of height of corrugation of webs are considered as the geometric parameters which would be expected to affect the ultimate behavior. By this analytical study with considering the geometric parameters, the changes of ultimate behavior and load carrying capacity of curved girders with corrugated webs are investigated. Also, the effects of corrugated webs on the increase of load carrying capacity for curved girders are studied with comparing to the capacity of general curved girders with flat webs. According to the analytical results, corrugated webs can be used to increase the ultimate load carrying capacity of curved girders, because of their high torsional and warping stiffness. But, it is also indicated that they may decrease the load carrying capacity of curved girders which have relatively small subtended angle or initial curvature, because of an accordion effect.

A Study on Compact Section Requirements for Plate Girder Web Panels with Longitudinal Stiffeners (수평보강재가 설치된 플레이트거더 복부판의 조밀기준에 관한 연구)

  • Lee, Myung Soo;Lee, Doo Sung;Lee, Sung Chul
    • KSCE Journal of Civil and Environmental Engineering Research
    • /
    • v.30 no.6A
    • /
    • pp.503-512
    • /
    • 2010
  • In AASHTO LRFD (2007), a compact section is defined as a section in which no premature failure caused by local buckling of web and flange plate or later buckling occurs before the section reaches the plastic moment, Mp. The current AASHTO LRFD (2007) provides the compact section requirement by limiting the web slenderness only for webs without longitudinal stiffeners. The role of longitudinal stiffener is to increase the web buckling strength caused flexure. Although a web does not satisfy the compactness requirement without longitudinal stiffeners, the web buckling can be prevented by use of valid longitudinal stiffeners. Therefore, the web may be able to reach the plastic moment. However, the reason why a longitudinal stiffener may not be used to satisfy compactness requirement is not cleary explained in AASHTO LRFD (2007). In this study, the buckling and ultimate strength behaviors of stiffened webs subjected to bending are investigated through the linear buckling and nonlinear finite element analysis. It is found that steel plate girders having webs that do not satisfy the compactness requirement are able to reach the plastic moment if the longitudinal stiffeners have sufficient rigidities and are properly located. From a nonlinear regression analysis of the results, a new compactness requirement is suggested for webs stiffened with one longitudinal stiffener.

Association between Korean Healthy Eating Index and abdominal obesity in Korean adults: the mediating effect of high-sensitivity C-reactive protein (한국 성인의 식생활평가지수 및 복부비만의 관계: 고감도 C-반응 단백질의 매개효과)

  • Jina Yoon;Dayeon Shin
    • Journal of Nutrition and Health
    • /
    • v.57 no.1
    • /
    • pp.88-104
    • /
    • 2024
  • Purpose: High-sensitivity C-reactive protein (hs-CRP) is primarily synthesized in the liver upon stimulation of infectious disease cytokines, such as interleukin-6 (IL-6), and is used as a biological marker of systemic inflammation. Previous studies reported that hs-CRP is closely related to diet and abdominal obesity. Furthermore, a dietary score favoring the consumption of vegetables, fruits, and whole grains over meat and saturated fat reduced inflammation and decreased the prevalence of obesity and abdominal obesity. Nevertheless, no studies have examined whether hs-CRP mediates the relationship between dietary scores and abdominal obesity, and research on the Korean Healthy Eating Index (KHEI) is lacking. Therefore, the present study examined the association between the KHEI and abdominal obesity and the mediating effect of hs-CRP. Methods: In total, 17,770 adults aged ≥19 years were included in the study using the Korea National Health and Nutrition Examination Survey 2015-2018. KHEI was developed to assess the overall diet quality of Korean adults. Multivariable linear and logistic regression analyses assessed the relationship between KHEI, hs-CRP, and abdominal obesity. The mediation analysis with the bootstrapping method was performed using SAS MACRO. Results: Among women, the odds ratio (OR) of abdominal obesity prevalence was lower in the highest KHEI compared to the lowest KHEI after adjusting for age, body mass index, educational level, income level, occupational status, marital status, household type, region type, alcohol consumption, smoking status, physical activity, total energy intake, and hsCRP (OR 0.744, 95% confidence interval 0.598-0.926). The association between KHEI and abdominal obesity was partially mediated via hs-CRP, and the mediated proportion was 68.7% in men and 38.1% in women. Conclusion: A substantial relationship was observed between the KHEI and abdominal obesity among females. Moreover, according to the KHEI, abdominal obesity may be mediated partially by hs-CRP.

Evaluation of Stress Characteristics and Rupture Risk of the Aortic Wall According to Abdominal Aortic Aneurysm Geometry and Age (복부대동맥류 형상 및 연령에 따른 동맥 벽 응력 특성 및 파열 위험성 평가)

  • Lee, Chung Won;You, Ji-Hun;Huh, Up;Lee, Chi-Seung;Ryu, Dong-Man
    • Journal of the Computational Structural Engineering Institute of Korea
    • /
    • v.33 no.3
    • /
    • pp.179-186
    • /
    • 2020
  • In this study, the wall stress and rupture risk for abdominal aortic aneurysms were calculated based on the age and geometry of the examined abdominal aortic aneurysms. The geometry of the abdominal aorta was simulated using computed tomography data from patients with abdominal aortic aneurysms. With regard to material properties, the Gasser-Ogden-Holzapfel model was applied to the analysis to simulate the anisotropic hyperelastic characteristics of the artery. In addition, each material parameter was estimated to consider the properties for age and for normal and aneurysm tissue. Moreover, the correlation between the diameter and angle of the aortic aneurysms was analyzed based on data from patients with abdominal aortic aneurysms, and series simulations were conducted. As a result, the rupture risk for the abdominal aortic aneurysms was evaluated based on the age and geometry of the aneurysm.

Immediate Effects of Abdominal Pressure Belt on Limited of Stability and Gait Parameter in Patients after Chronic Stroke: one-group pretest-posttest design (복부압박벨트가 만성 뇌졸중 환자의 균형 및 보행에 즉각적으로 미치는 융복합적 영향)

  • Park, Shin-Jun;Cho, Kyun-Hee
    • Journal of the Korea Convergence Society
    • /
    • v.11 no.4
    • /
    • pp.63-69
    • /
    • 2020
  • This study was conducted to investigate the immediate effects of abdominal pressure blet on limited of stability and gait parameter in patients after stroke. Thirty stroke patients were recruited to measured pre and post wearing the abdominal pressure belt. The assessment measured limited of stability and spatiotemporal gait parameter. This study result were significantly increase in paretic side area, non-paretic side area, forward side area, backward side area (p<.05) and cadence, gait velocity, stride length (p<.05). This study found that abdominal pressure belt had an immediate effect on improving balance and gait function in stroke patients. Future studies require studies of efficient abdominal pressure levels and intervention periods to improve the balance and walking function of stroke patient.

Experimental Study on Ultimate Shear Behaviour of Longitudinally Stiffened Plate Girder Web Panels (수평보강재가 있는 판형복부판의 극한전단거동에 관한 실험연구)

  • Lee, Myung Soo
    • Journal of Korean Society of Steel Construction
    • /
    • v.11 no.2 s.39
    • /
    • pp.167-179
    • /
    • 1999
  • The thin web panels of plate girders often need to be reinforced with transverse stiffeners to increase the shear strength. Since early 1960s, extensive researches have been conducted on the ultimate shear strength of plate girder webs with transverse stiffeners. These results have been first adopted into AASHTO(1970) and British Standard(1983) Specifications for the determination of the ultimate shear strength of transversely stiffened web panels. Although the main purposes of reinforcing web panels with longitudinal stiffeners are to increase the buckling strength and to control the lateral deflections due to bending, it has been reported that the longitudinal stiffeners increase the shear strength. However lack of studies has kept the effects of the longitudinal stiffeners on the ultimate shear strength from the design of plate girder web panels. In the present study an experimental investigation is carried out in order to assess the increment of the ultimate shear strength of shear web panels due to the longitudinal stiffeners and the results are compared with the existing failure theories.

  • PDF

Usefulness of Abdominal Fat Measured by Computed Tomography and Bioelectric Impedance Analysis as an Obesity Index (컴퓨터단층촬영과 생체전기 저항 분석법으로 측정된 복부지방의 비만지표로서의 유용성)

  • Kim, Mi-Young;Kim, Hwa-Sun
    • The Journal of the Korea Contents Association
    • /
    • v.11 no.12
    • /
    • pp.807-813
    • /
    • 2011
  • For obesity management requires accurate measurement of abdominal fat. The purpose of this study was to find out the correlation between abdominal fat and lipid measured with BIA and CT. Secondly, This study investigate for usefulness of abdominal fat measured by BIA and CT as an obesity index. As a result, TG showed higher value in the overweight obese group than normal group but HDL showed lower value in the overweight obese group than normal group. TG and HDL appeared significantly relationship with by BIA and CT in the normal group. However, in the overweight obese group TG showed significantly relationship with the BIA. According to multiple regression analysis on BMF and TAF was affected by HDL in the normal group. And BMF, %BF was affected by TG in overweight obese group. In conclusion, abdominal fat showed significant correlation with lipid. Abdominal fat measured by BIA and CT to assess obesity index is considered as a useful way to evaluate.

A Comparison Analysis of CT Effective Dose and Image Quality according to Abdominal Diameter (복부직경에 따른 CT유효선량 및 화질변화 비교 분석)

  • Yoon, Joon;Kim, Hyeonju
    • Journal of the Korean Society of Radiology
    • /
    • v.12 no.7
    • /
    • pp.821-826
    • /
    • 2018
  • This study was performed randomly from all the patients who visited the University Hospital in Gyeonggi-do from January 1, 2018 to June 30, 2018 for the abdominal CT scan. We divided the patients into three groups and evaluated the extent of effective dose and image quality according to the area of the abdominal CT image. As a result, the effective dose was 7.34 mSv in the average area group, 8.39 mSv in the average area and 5.89 mSv in the average area. For the analysis of image quality, ROI was plotted in the same three regions according to the abdominal area. As a result, CT values were significantly different in the abdominal area classified into 3 groups (p <0.05). The results of this study can be used as a basic data for the development of a protocol that can be applied in actual clinical practice. It is thought that it can help to reduce the image quality and the radiation dose.

A Study on Elastic Shear Buckling Coefficients of Horizontally Curved Plate Girder Web Panels (강곡선 플레이트거더 복부판의 전단좌굴계수에 관한 연구)

  • Lee, Doo-Sung;Lee, Sung-Chul
    • KSCE Journal of Civil and Environmental Engineering Research
    • /
    • v.28 no.3A
    • /
    • pp.367-373
    • /
    • 2008
  • In the design of horizontally curved plate girder web panels, it is required to evaluate accurately the elastic buckling strength under pure shear. Currently, elastic shear buckling coefficients of curved web panels stiffened by transverse intermediate stiffeners are determined by assuming conservatively that straight web panels without curvature are simply supported at the juncture between the flange and web. However, depending upon the geometry and the properties of the curved plate girder, the elastically restrained support may behave rather closer to a fixed support. The buckling strength of curved girder web is much greater (maximum 38%) than that of a straight girder calculated under the assumption that all four edges are simply supported in Lee and Yoo (1999). In the present study, a series of numerical analyses based on a 3D finite element modeling is carried out to investigate the effects of geometric parameters on both the boundary condition at the juncture and the horizontal curvature of web panel, and the resulting data are quantified in a simple design equation.

The Rigidity of Transverse Intermediate Stiffener of Horizontally Curved Plate Girder Web Panels (강곡선 플레이트거더 복부판의 중간수직보강재 소요강성에 관한 연구)

  • Lee, Doo Sung;Park, Chan Sik;Lee, Sung Chul
    • KSCE Journal of Civil and Environmental Engineering Research
    • /
    • v.26 no.4A
    • /
    • pp.735-742
    • /
    • 2006
  • In this study, the ultimate shear strength behavior of transversely stiffened curved web panels was investigated through nonlinear finite element analysis. It was found that if the transverse stiffener has a sufficient rigidity, then curved web panels used in practical designs are able to develop the postbuckling strength that is equivalent to that of straight girder web panels having the same dimensional and material properties. The nonlinear analysis results indicate that in order for curved web panels to develop the potential postbuckling strength. The rigidity of the transverse stiffener needs to be increased several times the value obtained from the Guide Specifications (AASHTO, 2003). However, in the case of thick web panels where the shear design is governed by shear yielding, the stiffener rigidity does not have to be increased. From the analysis results, a simple design formula is suggested for the rigidity of transverse stiffener under strength limit state.