• Title/Summary/Keyword: Asymmetry effect

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Dynamic Behaviors of the Curved Steel Tunnel Lining due to Wind Loads by Passing Vehicles (통과차량으로 인한 풍하중에 대한 곡선 강재 터널라이닝의 동적 거동 분석)

  • Mha, Ho-Seong;Cho, Kwang-Il;Park, Inn-Joon
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.14 no.4
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    • pp.309-320
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    • 2012
  • Dynamic behaviors of the tunnel linings of curved tunnels with various curvatures are investigated to examine the effect of wind loads due to passing vehicles. In the case without backfill, the responses of the tunnel lining should be considered to examine the clearance of the lining. A steel tunnel lining is selected to see the influence of the wind load upon the tunnel lining more clearly. The wind pressure upon the lining is simplified into the pressure and suction while the vehicle passing the loading positions. As the radius of curvature decreases, the response decreases, showing that the strength against the deformation is found to increase since the asymmetry of the deformation shape is reduced. It is found that the responses increase as the passing vehicle speed increases.

The effect of Reynolds number on the elliptical cylinder wake

  • Shi, Xiaoyu;Alam, Md. Mahbub;Bai, Honglei;Wang, Hanfeng
    • Wind and Structures
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    • v.30 no.5
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    • pp.525-532
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    • 2020
  • This work numerically investigates the effects of Reynolds number ReD (= 100 - 150), cross-sectional aspect ratio AR = ( 0.25 -1.0), and attack angle α (= 0° - 90°) on the forces, Strouhal number, and wake of an elliptical cylinder, where ReD is based on the freestream velocity and cylinder cross-section height normal to the freestream flow, AR is the ratio of the minor axis to the major axis of the elliptical cylinder, and α is the angle between the cylinder major axis and the incoming flow. At ReD = 100, two distinct wake structures are identified, namely 'Steady wake' (pattern I) and 'Karman wake followed by a steady wake (pattern II)' when AR and α are varied in the ranges specified. When ReD is increased to 150, an additional wake pattern, 'Karman wake followed by secondary wake (pattern III)' materializes. Pattern I is characterized by two steady bubbles forming behind the cylinder. Pattern II features Karman vortex street immediately behind the cylinder, with the vortex street transmuting to two steady shear layers downstream. Inflection angle αi = 32°, 37.5° and 45° are identified for AR = 0.25, 0.5 and 0.75, respectively, where the wake asymmetry is the greatest. The αi effectively distinguishes the dependence on α and AR of force and vortex shedding frequency at either ReD. In Pattern III, the Karman street forming behind the cylinder is modified to a secondary vortex street. At a given AR and α, ReD = 150 renders higher fluctuating lift and Strouhal number than ReD = 100.

Effect of Cash flow on the R&D investment of Pharmaceutical Companies - focused on KOSDAQ market (제약회사의 현금흐름이 연구개발투자에 미치는 영향 -코스닥시장을 중심으로)

  • Lee, Munjae;Choi, Mankyu
    • The Journal of the Korea Contents Association
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    • v.15 no.8
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    • pp.473-480
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    • 2015
  • The purpose of this study is to analyze the influence of the cash flow of pharmaceutical companies on R&D investment. 143 pharmaceutical companies listed in the KOSDAQ market from 2009 to 2013. Financial statements and comments in general and internal transactions were extracted from TS-2000 of the Korea Listed Company Association (KLCA), and data related to stock price was extracted from KISVALUE-III of NICE Information Service Co., Ltd. STATA 12.0 was used as the statistical package for panel analysis. The summary of the findings and the interpretation of the significance of this are as follows: First, the current ratio (internal finance) had a positive influence on R&D investment. Second, the debt ratio (external finance) had a negative influence on R&D investment. The pharmaceutical company prefers internal funds to external funds due to the asymmetry of information in the loan markets. In other words, this shows why internal finances have a significant influence on R&D investment at pharmaceutical companies.

Phenomenological Modeling of Newly Discovered Eclipsing Binary 2MASS J18024395 + 4003309 = VSX J180243.9+400331

  • Andronov, Ivan L.;Kim, Yonggi;Kim, Young-Hee;Yoon, Joh-Na;Chinarova, Lidia L.;Tkachenko, Mariia G.
    • Journal of Astronomy and Space Sciences
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    • v.32 no.2
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    • pp.127-136
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    • 2015
  • We present a by-product of our long term photometric monitoring of cataclysmic variables. 2MASS J18024395 +4003309 = VSX J180243.9 +400331 was discovered in the field of the intermediate polar V1323 Her observed using the Korean 1-m telescope located at Mt. Lemmon, USA. An analysis of the two-color VR CCD observations of this variable covers all the phase intervals for the first time. The light curves show this object can be classified as an Algol-type variable with tidally distorted components, and an asymmetry of the maxima (the O'Connell effect). The periodogram analysis confirms the cycle numbering of Andronov et al. (2012) and for the initial approximation, the ephemeris is used as follows: Min I. BJD = 2456074.4904+0.3348837E. For phenomenological modeling, we used the trigonometric polynomial approximation of statistically optimal degree, and a recent method "NAV" ("New Algol Variable") using local specific shapes for the eclipse. Methodological aspects and estimates of the physical parameters based on analysis of phenomenological parameters are presented. As results of our phenomenological model, we obtained for the inclination $i=90^{\circ}$, $M_1=0.745M_{\odot}$, $M_2=0.854M_{\odot}$, $M=M_1+M_2=1.599M_{\odot}$, the orbital separation $a=1.65{\cdot}10^9m=2.37R_{\odot}$ and relative radii $r_1=R_1/a=0.314$ and $r_2=R_2/a=0.360$. These estimates may be used as preliminary starting values for further modeling using extended physical models based on the Wilson & Devinney (1971) code and it's extensions

Premotor-time of the Ankle Muscle during Bilateral Contraction in the Elderly (고령자의 족관절 근육 양측성 수축시의 전운동 반응시간)

  • Kim, Ji-Won;Kwon, Yu-Ri;Shin, Jae-Nam;Eom, Gwang-Moon;Kim, Chul-Seung;Park, Byung-Kyu;Hong, Jung-Hwa
    • Journal of Biomedical Engineering Research
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    • v.31 no.3
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    • pp.245-250
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    • 2010
  • The purpose of this study is to investigate the effects of sex and age and their interactions in premotor-time (PMT) of ankle muscle. Forty-eight elderly subjects (aged 65-90 years) and thirty young subjects (aged 19-27 years) participated in this study. Subject were instructed to perform maximal, voluntary, isometric, bilateral contraction of ankle muscle in reaction to auditory stimulus to determine PMT. As analysis variables, PMT, intrasubject variability of PMT and asymmetry of PMT between dominant and nondominant legs were used. As statistical analysis, two-way ANOVA was performed to assess the main effects of age group and sex and also their interactions. All variables showed significant age effects (p<0.01). However, no sex effect and interaction existed in all variables in both dominant and nondomiant legs. Theses results suggest that the PMT of ankle muscle is related to the age-related deterioration in postural control, however, not related to the sex-difference of fall incidence in the elderly population.

Metformin Association with Lower Prostate Cancer Recurrence in Type 2 Diabetes: a Systematic Review and Meta-analysis

  • Hwang, In Cheol;Park, Sang Min;Shin, Doosup;Ahn, Hong Yup;Rieken, Malte;Shariat, Shahrokh F.
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.2
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    • pp.595-600
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    • 2015
  • Background: Accumulating evidence suggests that metformin possesses anticarcinogenic properties, and its use is associated with favorable outcomes in several cancers. However, it remains unclear whether metformin influences prognosis in prostate cancer (PCa) with concurrent type 2 diabetes (T2D). Materials and Methods: We searched PubMed, EMBASE, and the Cochrane Library from database inception to April 16, 2014 without language restrictions to identify studies investigating the effect of metformin treatment on outcomes of PCa with concurrent T2D. We conducted a meta-analysis to quantify the risk of recurrence, progression, cancer-specific mortality, and all-cause mortality. Summary relative risks (RRs) with corresponding 95% confidence intervals (CIs) were calculated. Publication bias was assessed by Begg's rank correlation test. Results: A total of eight studies fulfilled the eligibility criteria. We found that diabetic PCa patients who did not use metformin were at increased risk of cancer recurrence (RR, 1.20; 95%CI, 1.00-1.44), compared with those who used metformin. A similar trend was observed for other outcomes, but their relationships did not reach statistical significance. Funnel plot asymmetry was not observed among studies reporting recurrence (p=0.086). Conclusions: Our results suggest that metformin may improve outcomes in PCa patients with concurrent T2D. Well-designed large studies and collaborative basic research are warranted.

A study on expression methods for structural aesthetics in modern fashion design - Focus on the architectural characteristics of Santiago Calatrava - (현대 구조적 패션디자인에 나타난 구조미의 표현방식에 대한 연구 - 산티아고 칼라뜨라바의 건축특성을 중심으로 -)

  • Lee, Yeonji;Um, Sohee
    • The Research Journal of the Costume Culture
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    • v.23 no.5
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    • pp.737-754
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    • 2015
  • The structural aesthetics of architecture are becoming an inspirational source for many fashion designers and have been reborn in structural fashion. This study planned to analyze the method of expression of structural aesthetics expressed in modern structural fashion design and the construction method to maximize such an effect on the basis of the construction characteristic of Santiago Calatrava as the representative architect of the structural aesthetic. According to the study, the structural aesthetics expressed in modern structural fashion design are as follows: 1) The symbolical formative aesthetic expressed by symbolical inference and analyzation; 2) the dynamic beauty of physic expressed by visual emphasis and dynamics; and 3) the asymmetric beauty of symmetry expressed by metastasis toward the boundary between balance and imbalance. In addition, to maximize structural aesthetics, we used repetition and a progressive technique based on rhythm, asymmetry, and incision-based variances, such as balance, polygon flux, and inference, and analyzation-based distortion as the structuring principle. The following expression methods for maximizing structural aesthetics were found: 1) symbolical and structural exaggeration of appearance; 2) detail technique expansion and material property diversification; and 3) the three-dimensional transformation of structure and shell expression. Structural fashion design was found to have maximized structural aesthetics by using such expression methods to secure artistic esthetics, destroy existing shapes and patterns, and create unique shapes.

Pooled Prevalence of Workplace Bullying in Nursing: Systematic Review and Meta-analysis (간호사간 직장내 괴롭힘 발생률에 관한 체계적 문헌고찰과 메타분석)

  • Kang, Jiyeon;Lee, Minju
    • Journal of Korean Critical Care Nursing
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    • v.9 no.1
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    • pp.51-65
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    • 2016
  • Purpose: This study aimed to estimate the pooled prevalence of workplace bullying among nurses and examine the effect of moderate factors. Methods: Studies that assessed nursing workplace bullying using the negative act questionnaire developed by Einarsen et al. were searched for in 8 databases. The pooled prevalence was calculated with overall event rate and meta-ANOVA was performed for subgroup analysis. A funnel plot and Egger's linear regression asymmetry test were performed to confirm the publication bias of meta-analyzed studies. Results: A total of 23 studies (N=11,748) were included in the systematic review, and 14 studies (N=4,585) that reported prevalence using operational criteria of victim were selected for meta-analysis. The pooled prevalence of workplace bullying was 22.2% (95% CI: 19.0~25.7). Domestic studies reported lower prevalence than international studies (18.6% vs. 27.0%, Q=8.75, p=.003). The prevalences were different according to publication year (30.6% in 2008~2010, 19.5% in 2011~2014, 21.8% in 2015, Q=11.89, p=.003). Studies that recruited only new nurses reported higher prevalence than others (28.4% vs. 20.6%, Q=3.92, p=.048). Publication bias was not found. Conclusions: Workplace bullying is prevalent in the nursing profession, and is more serious for new graduate nurses. Individual and organizational measures for preventing workplace bullying among nurses need to be sought.

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The Clinical Study of Muscle Energy Techniques in Elector Spinae Muscle through Meridian Electromyography on Subjects (일반인에서의 근에너지 기법 시술 전과 후의 척추기립근 경근전도 변화)

  • Choi, Jin-Seo;Ahn, Jae-Min;Park, Dong-Su;Jeong, Su-Hyeon;Kim, Soon-Joong
    • The Journal of Churna Manual Medicine for Spine and Nerves
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    • v.7 no.2
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    • pp.101-108
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    • 2012
  • Objectives : To evaluate the clinical utility of Muscle Energy Techniques(MET) in Elector Spinae Muscle on subjects. Methods : We compared electrical activity between a before MET and a after MET in Elector Spinae Muscle on subjects in same group(n=26) in dynamic flexion-reextension state during five seconds. We analyzed amplitudes and areas of electrical activity and Asymmetry Index(AI) and Median Edge Frequency(MEF). Results : 1. After MET in Elector Spinae Muscle on subjects were lower electrical activity than before MET in Elector Spinae Muscle on subjects but it is not a pointless observation(p<0.05). 2. AI of the after MET in Elector Spinae Muscle on subjects significantly decreased compared with before MET in Elector Spinae Muscle on subjects(p<0.05). 3. MEF of the after MET in Elector Spinae Muscle on subjects decreased compared with before MET in Elector Spinae Muscle on subjects but it is not a pointless observation(p<0.05). Conclusions : According to above results, there is clinical effect MET on subjects.

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Detection of MicroRNA-21 Expression as a Potential Screening Biomarker for Colorectal Cancer: a Meta-analysis

  • Jiang, Jian-Xin;Zhang, Na;Liu, Zhong-Min;Wang, Yan-Ying
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.18
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    • pp.7583-7588
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    • 2014
  • Background: Colorectal cancer (CRC) is a major cause of cancer-related death and cancer-related incidence worldwide. The potential of microRNA-21 (miR-21) as a biomarker for CRC detection has been studied in several studies. However, the results were inconsistent. Therefore, we conducted the present meta-analysis to systematically assess the diagnostic value of miR-21 for CRC. Materials and Methods: Using a random-effect model, the pooled sensitivity (SEN), specificity (SPE), positive likelihood ratio (PLR), negative likelihood ratio (NLR), and diagnostic odds ratio (DOR) were calculated to evaluate the diagnostic performance of miR-21 for CRC. A summary receiver operating characteristic (SROC) curve and an area under the curve (AUC) were also generated to assess the diagnosis accuracy of miR-21 for CRC. Q test and I2 statistics were used to assess between-study heterogeneity. Publication bias was evaluated by the Deeks' funnel plot asymmetry test. Results: A total of 986 CRC patients and 702 matched healthy controls from 8 studies were involved in the meta-analysis. The pooled results for SEN, SPE, PLR, NLR, DOR, and AUC were 57% (95%CI: 39%-74%), 87% (95%CI: 78%-93%), 4.4 (95%CI: 2.4-8.0), 0.49 (95%CI: 0.32-0.74), 9 (95%CI: 4-22), and 0.83 (95%CI: 0.79-0.86), respectively. Subgroup analyses further suggested that blood-based studies showed a better diagnostic accuracy compared with feces-based studies, indicating that blood may be a better matrix for miR-21 assay and CRC detection. Conclusions: Our findings suggest that miR-21 has a potential diagnostic value for CRC with a moderate level of overall diagnostic accuracy. Hence, it could be used as auxiliary means for the initial screening of CRC and avoid unnecessary colonoscopy, which is an invasive and expensive procedure.