• Journal of Gastric Cancer
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• 제15권4호
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• pp.238-245
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• 2015

Purpose: This study aimed to identify time-dependent prognostic factors and demonstrate the time-dependent effects of important prognostic factors in patients with advanced gastric cancer (AGC). Materials and Methods: We retrospectively evaluated 3,653 patients with AGC who underwent curative standard gastrectomy between 1991 and 2005 at the Korea Cancer Center Hospital. Multivariate survival analysis with Cox proportional hazards regression was used in the analysis. A non-proportionality test based on the Schoenfeld residuals (also known as partial residuals) was performed, and scaled Schoenfeld residuals were plotted over time for each covariate. Results: The multivariate analysis revealed that sex, depth of invasion, metastatic lymph node (LN) ratio, tumor size, and chemotherapy were time-dependent covariates violating the proportional hazards assumption. The prognostic effects (i.e., log of hazard ratio [LHR]) of the time-dependent covariates changed over time during follow-up, and the effects generally diminished with low slope (e.g., depth of invasion and tumor size), with gentle slope (e.g., metastatic LN ratio), or with steep slope (e.g., chemotherapy). Meanwhile, the LHR functions of some covariates (e.g., sex) crossed the zero reference line from positive (i.e., bad prognosis) to negative (i.e., good prognosis). Conclusions: The time-dependent effects of the prognostic factors of AGC are clearly demonstrated in this study. We can suggest that time-dependent effects are not an uncommon phenomenon among prognostic factors of AGC.

• 대한인간공학회지
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• 제28권4호
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• pp.61-69
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• 2009

With increasing needs for affective design, it became an essential part in a product development process to look up quantitative ergonomic data that reflects customers' preferences on design factors in various products. This study looked at wide LCD monitors and analyzed customers' affective preferences regarding monitor's bezel frame size and shape. The monitor's bezel frame depth, size and ratio were selected as independent variables among many design parameters. As dependent variables, customer's subjective preferences were measured. A statistical analysis revealed that monitor's bezel frame depth, size and ratio had significant effects on customer's preferences. Also, it was possible to find a different tendency on affective variables and their levels for 19" and 24" wide LCD monitors. In general, experiments revealed that customers reacted more sensitively in 24" wide LCD monitors to all variables. In 19" wide LCD monitors, only the lower frame bezel size had a significant effect, otherwise, lower, upper and side frame bezels appeared to be effective variables in 24" monitors. In order to reflect customer's affective preferences to new design of wide LCD monitors, this study is expected to provide quantitative ergonomic data and guidelines for the design of wide LCD monitor's bezel frame depth and size.

• The Journal of Korean Physical Therapy
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• 제33권5호
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• pp.211-216
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• 2021

Purpose: The main purpose of this meta-analysis was to identify the degree of effect size and variables for the impact of manual physical therapy on the improvement in the range of motion of frozen shoulder patients. Methods: This study collected 8 studies published between 1st January 2010 and 31st December 2020. The analysis of the results verified 49 effect size data and the random effect model was chosen. Results: First, the full case showed the largest mean effect size of 2.485 (p<0.001). Second, the size of the effect based on manual therapy and modality therapy showed an effect size of 4.178 (p<0.001). Third, the outcome group included 6 variables. The external rotation (2.818) variable group showed the largest mean effect size, followed by internal rotation (2.748), flexion (2.643), abduction (2.356), and adduction (2.356). Six outcomes were significant and the mean effect sizes of all the varied groups were above large size. The number of participants showed a 20 or less effect size of 2.478 (p>0.737). The number of intervention periods showed 4 weeks 20 or more effect size of 2.782 (p>0.294). Finally, the 'Trim and Fill' result confirmed that the calibration effect size was 1.471 (p<0.001). Conclusion: This study verified that manual physical therapy had a substantial effect on the improvement of the range of motion of patients with frozen shoulders and that the effects were dependent on the methods of outcomes.

• Structural Engineering and Mechanics
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• 제53권3호
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• pp.497-517
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• 2015

In this study, nonlocal nonlinear buckling analysis of embedded polymeric temperature-dependent microplates resting on an elastic matrix as orthotropic temperature-dependent elastomeric medium is investigated. The microplate is reinforced by single-walled carbon nanotubes (SWCNTs) in which the equivalent material properties nanocomposite are estimated based on the rule of mixture. For the carbon-nanotube reinforced composite (CNTRC) plate, both cases of uniform distribution (UD) and functionally graded (FG) distribution patterns of SWCNT reinforcements are considered. The small size effects of microplate are considered based on Eringen's nonlocal theory. Based on orthotropic Mindlin plate theory along with von K$\acute{a}$rm$\acute{a}$n geometric nonlinearity and Hamilton's principle, the governing equations are derived. Generalized differential quadrature method (GDQM) is applied for obtaining the buckling load of system. The effects of different parameters such as nonlocal parameters, volume fractions of SWCNTs, distribution type of SWCNTs in polymer, elastomeric medium, aspect ratio, boundary condition, orientation of foundation orthtotropy direction and temperature are considered on the nonlinear buckling of the microplate. Results indicate that CNT distribution close to top and bottom are more efficient than those distributed nearby the mid-plane for increasing the buckling load.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2013년도 추계학술대회 논문집
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• pp.109-110
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• 2013

• Geomechanics and Engineering
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• 제36권1호
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• pp.83-97
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• 2024

It is important to make reasonable prediction about the long-term deformation of high rockfill geostructures. However, the deformation is usually underestimated using the rockfill parameters obtained from laboratory tests due to different size effects, which make it necessary to identify parameters from in-situ monitoring data. This paper proposes a novel hybrid back-analysis method with a modified objective function defined for the time-dependent back-analysis problem. The method consists of two stages. In the first stage, an improved weighted average method is proposed to quickly narrow the search region; while in the second stage, an adaptive response surface method is proposed to iteratively search for the satisfactory solution, with a technique that can adaptively consider the translation, contraction or expansion of the exploration region. The accuracy and computational efficiency of the proposed hybrid back-analysis method is demonstrated by back-analyzing the long-term deformation of two high embankments constructed for airport runways, with the rockfills being modeled by a rheological model considering the influence of stress states on the creep behavior.

• Computers and Concrete
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• 제14권4호
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• pp.369-385
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• 2014

In the existing method for analyzing the liquid tightness of the outer concrete tank in an emergency LNG spillage, the temperature variation over time inside the tank, and the concrete properties dependent on temperature and internal moisture content, have not been taken into account. In this study, the analyses for a typical LNG concrete tank subjected to thermal load due to spillage were performed with three different cases: the existing method was adopted in the first case, the transient temperature variation was considered in the second, and the temperature-moisture content dependent concrete properties were taken into account as well as the transient states of temperature in the third. The analysis results for deformation, compressive zone size, cracking, and stress of reinforcements were compared, and a discussion on the difference between the results obtained from the different analysis cases was made.

• Journal of Microbiology and Biotechnology
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• 제30권3호
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• pp.341-351
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• 2020

To shed light on the genetic differences among food-originated coagulase-negative Staphylococcus (CNS), we performed pan-genome analysis of five species: Staphylococcus carnosus (two strains), Staphylococcus equorum (two strains), Staphylococcus succinus (three strains), Staphylococcus xylosus (two strains), and Staphylococcus saprophyticus (one strain). The pan-genome size increases with each new strain and currently holds about 4,500 genes from 10 genomes. Specific genes were shown to be strain dependent but not species dependent. Most specific genes were of unknown function or encoded restriction-modification enzymes, transposases, or prophages. Our results indicate that unique genes have been acquired or lost by convergent evolution within individual strains.

• Bulletin of the Korean Chemical Society
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• 제35권9호
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• pp.2621-2624
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• 2014

The rapid and spontaneous adsorption of proteins on nanoparticle (NP) surfaces in biological fluids such as blood is an important phenomenon as it possibly determines "what the cells see" and, thus, the fates of NPs in living organisms. In order to quantitatively understand protein coronas at the molecular level, we investigated human serum albumin (HSA) coronas that were produced on silica NPs of 20 nm and 50 nm diameters using conventional gel electrophoresis. Analysis of the concentration dependence of protein adsorption showed that HSA coronas preferentially formed a monolayer on silica NPs and revealed the presence of hard protein coronas. HSA adsorption was clearly dependent on NP size, and this might be due to the different surface curvatures of NPs of different sizes.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2004년도 추계학술대회 논문집
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• pp.413-417
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• 2004

Recent experiments have shown the 'size effects' in micro/nano scale. But the classical plasticity theories can not predict these size dependent deformation behaviors because their constitutive models have no characteristic material length scale. The Mechanism - based Strain Gradient(MSG) plasticity is proposed to analyze the non-uniform deformation behavior in micro/nano scale. The MSG plasticity is a multi-scale analysis connecting macro-scale deformation of the Statistically Stored Dislocation(SSD) and Geometrically Necessary Dislocation(GND) to the meso-scale deformation using the strain gradient. In this research we present a study of nano-indentation by the MSG plasticity. Using W. D. Nix and H. Gao s model, the analytic solution(including depth dependence of hardness) is obtained for the nano indentation , and furthermore it validated by the experiments.