• Structural Engineering and Mechanics
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• v.49 no.3
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• pp.297-309
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• 2014

Under lateral loads Framed Tube (FT) system exhibits reduction of cantilever efficiency due to the effect of shear lag. Braced Tube (BT) represents a valuable solution to overcome shear lag problems by stiffening the exterior frame with diagonal braced members. This study investigates the effect of shear lag on BT and FT under wind load. Shear lag and top-level displacement results are compared with previous findings by researchers on FT and BT systems. The investigation of the effect of various configurations in BT on the reduction the shear lag is another objective of this study. The efficiency of each structure is evaluated using the linear response spectrum analysis to obtain shear lag. STADD Pro software is used to run the dynamic analysis of the models. Results show there is relatively less shear lag in all the BT configurations compared to the FT structural system. Moreover, the comparison of the obtained result with those derived by previous studies shows that shear lag is not proportional to lateral displacement. With respect to results, optimum BT configuration in term of lower shear lag caused by lateral loads is presented.

• Research in Plant Disease
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• v.15 no.3
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• pp.254-258
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• 2009

An isolate of Cucumber mosaic virus (CMV), called as Lag-CMV, was identified from Lagenaria leucantha var. gourda showing mosaic symptom, and its properties was compared to Fny-CMV (subgroup IA) and As-CMV (subgroup IB) by host reaction in several indicator plants, dsRNA analysis, RT-PCR analysis, restriction enzyme profile of the PCR products and nucleotide sequence of coat protein gene. Lag-CMV was similar to As-CMV used as a control CMV by the induced chlorotic spot on inoculated leaves and mosaic symptoms on upper leaves of N. tabacum. cv. Xanthi nc. In the cucumber and zucchini squash, Lag-CMV and As-CMV induced a mild mosaic symptoms than that of Fny-CMV. Size and shapes of local lesions on Chenophodium amaranticolor and Vigna unguiculata induced by Lag-CMV was similar those by Fny-CMV or As-CMV. In experiments of dsRNA profiles and RT-PCR analysis of coat protein gene, Lag-CMV was come within subgroup I CMV. Moreover, restriction enzyme analysis using EcoRI, SalI, MspI, XhoI, and HindIII of the RTPCR products and nucleotide sequence analysis of the coat protein gene showed that Lag-CMV belong to a member of CMV subgroup IB of the same to As-CMV.

• Geomechanics and Engineering
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• v.21 no.5
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• pp.447-459
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• 2020

This paper aims to investigate the effect of rotation on a micropolar thermoelastic medium with voids problem. The problem is assessed according to three-phase-lag model. The normal mode analysis used to obtain the analytical expressions of the considered variables. The non-dimensional displacement, temperature, Micro rotation, the change in the volume fraction field, and stress of the material are obtained and illustrated graphically. Comparisons are made with the results predicted by two theories; namely three- phase-lag model (3PHL) and Green-Naghdi theory of type III (G-N III). The considered variables were plotted for different values of the rotation parameter, the phase-lag of heat flux and the phase-lag of temperature. The numerical results reveal that the rotation and the phase-lag times significantly influence the distribution of the field quantities. Some particular cases of interest are deduced from the present investigation.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2001.04a
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• pp.215-222
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• 2001

This study investigates the shear lag phenomenon existing in the shear wall of the wall-frame structure. Elastic analysis of such structures is carried out using a 3-D frame analysis program. The structural parameters governing the shear lag phenomenon are wall height and thickness. The analysis shows that the overturning moment due to external lateral load is resisted by both of the shear/core wall and the external frame. Severe unstable stresses are identified in height ratio of about 0.7 The taller or thinner wall shows the smaller shear lag phenomenon.

• Structural Engineering and Mechanics
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• v.84 no.3
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• pp.295-310
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• 2022

This paper proposes a modified bar simulation method for analyzing the shear lag effect of variable sectional box girder with multiple cells. This theoretical method formulates the equivalent area of stiffening bars and the allocation proportion of shear flows in webs, and re-derives the governing differential equations of bar simulation method. The feasibility of the proposed method is verified by the model test and finite element (FE) analysis of a simply supported multi-cell box girder with constant depth. Subsequently, parametric analysis is conducted to explore the mechanism of shear lag effect of varied sectional cantilever box girder with multiple cells. Results show that the shear lag behavior of variable box-section cantilever box girder is weaker than that of box girder with constant section. It is recommended to make the gradient of shear flow in the web with respect to span length vary as smoothly as possible for eliminating the shear lag effect of box girder. An effective countermeasure for diminishing shear lag effect is to increase the number of box chambers or change the variation manner of bridge depth. The shear lag effect of varied sectional cantilever box girder will get more server when the length of central flanges is shorter than 0.26 or longer than 0.36 times of total width of top flange, as well as the cantilever length exceeds 0.29 times of total length of box's flange. Therefore, the distance between central webs can adjust the shear lag effect of box girder. Especially, the width ratio of cantilever plate with respect to total length of top flange is proposed to be no more 1/3.

• Journal of Gastric Cancer
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• v.12 no.1
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• pp.18-25
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• 2012

Purpose: Recently, laparoscopy-assisted gastrectomy (LAG) has been widely accepted modality for early gastric cancer in Korea. The indication of LAG may be extended in an experienced institution. In our institution, the first case of laparoscopy-assisted gastrectomy (LAG) for gastric cancer was performed in May 1998. We retrospectively reviewed the long-term oncologic outcomes over 12 years to clarify the feasibility of LAG for gastric cancer. Materials and Methods: The authors retrospectively analyzed 753 patients who underwent LAG for gastric cancer, from May 1998 to August 2010. We reviewed clinicopathological features, postoperative outcomes, mortality and morbidity, recurrence, and survival of LAG for gastric cancer. Results: During the time period, 3,039 operations for gastric cancer were performed. Among them, 753 cases were done by LAG (24.8%). There were 69 cases of total gastrectomy, 682 subtotal gastrectomies, and 2 proximal gastrectomies. According to TNM stage, 8 patients were in stage 0, 619 in stage I, 88 in stage II, and 38 in stage III. The operation-related complications occurred in 77 cases (10.2%). Median follow-up period was 56.2 months (range 0.7~165.6 months). Twenty-five patients (3.3%) developed recurrence, during the follow-up period. The overall 5-year and disease free survival rates were 97.1% and 96.3%, respectively. Conclusions: The number of postoperative complications and survival rates of our series were comparable to the results from that of other reports. The authors consider LAG to be a feasible alternative for the treatment of early gastric cancer. However, rationale for laparoscopic surgery in advanced gastric cancer has yet to be determined.

• Journal of Astronomy and Space Sciences
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• v.29 no.3
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• pp.253-258
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• 2012

We revisit the relation between the peak luminosity $L_{iso}$ and the spectral time lag in the source frame. Since gamma-ray bursts (GRBs) are generally thought to be beamed, it is natural to expect that the collimation-corrected peak luminosity may well correlate with the spectral time lag in the source frame if the lag-luminosity relation in the GRB source frame exists. With 12 long GRBs detected by the Swift satellite, whose redshift and spectral lags in the source frame are known, we computed $L_{0,H}$ and $L_{0,W}$ using bulk Lorentz factors ${\Gamma}_{0,H}$ and ${\Gamma}_{0,W}$ archived in the published literature, where the subscripts H and W represent homogeneous and wind-like circumburst environments, respectively. We have confirmed that the isotropic peak luminosity correlates with the spectral time lag in the source frame. We have also confirmed that there is an anti-correlation between the source-frame spectral lag and the peak energy, $E_{peak}$ (1 + z) in the source frame. We have found that the collimation-corrected luminosity correlates in a similar way with the spectral lag, except that the correlations are somewhat less tight. The correlation in the wind density profile seems to agree with the isotropic peak luminosity case better than in the homogeneous case. Finally we conclude by briefly discussing its implications.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.3
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• pp.119-126
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• 2021

This study is to examine the foreign direct investment (FDI) response to real effective exchange rate volatility in Vietnam by using the vector autoregression model. The research data are quarterly frequency data in the period from 2004:Q1 to 2019:Q2. The data on real effective exchange rate were collected from the statistics of Bruegel (Europe) and FDI data were collected from the International Financial Statistics. The quantitative study was conducted with two steps: (1) measuring exchange rate volatility by the GARCH(1,1) method; and (2) examining the impact of exchange rate volatility on FDI in the context of the global financial crisis. The estimation results show that FDI responded significantly to real exchange rate volatility with the lag of 3 periods at the 5% significance level. The FDI response increased after the exchange rate volatility with the lag of 3 periods, and the impact extended to the lag of 6 periods, and then gradually stabilized. The research findings indicate that FDI in Vietnam responds positively and significantly to exchange rate volatility with the lag of 3 periods. Simultaneously, the negative impact of the global financial crisis in 2008 with the lag of 2 periods leads to a slight decrease in FDI inflows into Vietnam.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.34 no.3
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• pp.6-13
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• 2006

Aerodynamic characteristics for two-dimensional cyclic motion profile of flapping airfoil in low Reynolds number flows are investigated. Plunging motion and lead-lag motion in the two dimensional space with different plunging and lead-lag amplitudes are combined to cyclic motion profile and the flow around the airfoil is simulated. Present result shows that the improved aerodynamic efficiencies for a given flapping airfoil by adding periodic lead-lag motion of airfoil rather than the pure plunging case. The thrust coefficient and lift coefficient are compared with each cycle during the flapping period and aerodynamic characteristics are obtained on upstroke motion and downstroke motion.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.12 no.3
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• pp.234-238
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• 2007

Three different tidal phase-lag references have been used by the tidal research community of Korea: Greek kappa (k), Local standard time zone ($135^{\circ}E$) phase-lag (g) and Greenwich phase-lag (G). This ununified tidal information system may induce confusion in understanding tidal characteristics and their variability and impede the development of tidal knowledge in Korea. In this study we closely explore the three phase-lag reference definition with respect to their mutual conversion. We also identify an incorrect phase-lag reference definition used in previous works and discuss what has led to this misunderstanding.