• Architectural research
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• v.24 no.2
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• pp.53-61
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• 2022

Irregularities in the structure are crucial factors in screening structural vulnerability under extreme loadings. Numerical analyses were carried out considering wind and seismic loadings for four structures with discrete irregularity: continuous and discontinuous beams with varied story levels, and L-shaped irregular buildings. Structural responses such as maximum displacements, bending moments, axial forces, torsions, and story drifts are evaluated as per the criteria and limits defined by ACI 318. The outcomes indicate that the frame system with beam discontinuity on the upper half of the height exhibits the best structural performance. The results also indicate that the asymmetrical design of the L-shaped model makes it more susceptible to damage when subjected to strong lateral loading conditions.

• Investigative Magnetic Resonance Imaging
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• v.20 no.3
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• pp.158-166
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• 2016

Purpose: To understand clinical significance of irregular interface between meningioma and adjacent brain parenchyma in predicting histological grading of tumor, focusing on brain parenchymal invasion. Materials and Methods: Pathologically confirmed 79 cases with meningiomas with pathological reports about the presence of parenchymal invasion were included. We defined the presence of interface irregularity as either spiculations or fuzzy margins between the tumor and brain parenchyma. We counted number of spiculations and measured ratio of fuzzy margin length to whole length of mass with consensus of two neuroradiologists. We classified the patients into Present group and Absent group, and the two groups were compared by using the Mann-Whitney U test. Statistical correlations between the presence of an interface irregularity and brain parenchymal invasion by the tumor as well as meningioma histological grade were tested with chi-square test. The optimal cutoff values of spiculation numbers and the ratio of fuzzy margins were determined. The sensitivity and specificity of number of spiculations, ratio of fuzzy margin and the presence of irregular interface as combined parameters for predicting the parenchymal invasion were calculated using ROC curve analysis. Results: Statistically significant differences were noted between the Present and Absent groups for number of spiculations and ratio of fuzzy margin (P = 0.038 and P = 0.028, respectively). The optimal cutoff value for number of spiculations (> 4.5 with 61.1% sensitivity and 68.9% specificity) and the ratio of fuzzy margin (> 0.24 with 66.7% sensitivity and 65.6% specificity) were determined. The sensitivity and specificity of interface irregularity as the combined parameters were 72% and 59%, respectively. The interface irregularity between tumor and brain parenchyma significantly correlated with not only brain parenchymal invasion (P = 0.001) and but also histological grade (P < 0.001). Conclusion: The interface irregularity between tumor and brain parenchyma in MRI can be a strong predictive factor for brain parenchymal invasion and high grade meningioma.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.10a
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• pp.535-538
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• 1997

Studied in this paper was the lateral displacement of railway vehicle using the multi-body dynamic simulation program (VAMPIRE) and the BASS 501. The lateral displacement of railway vehicle is occurred by thc clearance between wheel flange and rail, the track irregularity, the property of each suspension of vehicle and the cant etc. The results of analysis shown that Vehicle is not interfere with subway platform in any conditions namely the tare and full load condition, the wheel. wear condition and the stationary and running of vehicle.

• Proceedings of the Korea Concrete Institute Conference
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• 2005.05a
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• pp.219-222
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• 2005

Many RC building structures of multiple uses constructed in Korea have the irregularities of torsion and soft story at bottom stories. A typical irregular building was selected as prototype and shaking table tests were performed to investigate the seismic performance of this building. The objective of this study is to evaluate the correlation between the experimental and analytical responses of this irregular building structure subjected to the earthquake excitation by using OpenSees(Open System for Earthquake Engineering Simulation). The results of analyses simulate well the behavior of the building having torsional irregularity and weak stories.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.965-968
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• 2005

Roll drafting operation causes variations in the linear density of bundles because the bundle flow cannot be controlled completely by roll pairs. Defects occurring in this operation bring about many problems successively in the next processes. In this paper, we attempt to analyze the draft dynamics and the linear density irregularity based on the governing equation of a bundle motion that has been suggested in our previous studies. For analyzing the dynamic characteristics of the roll drafting operation, it is indispensable to investigate a transient state in time domain before the bundle flux reaches a steady state. However, since governing equations of bundle flow consisting of continuity and motion equations turn out to be nonlinear, and coupled between variables, the solutions for a transient state cannot be obtained by an analytical method. Therefore, we use the Finite Difference Method(FDM), particularly, the FTBS(Forward-Time Backward-Space) difference method. Then, the total equations system yields to an algebraic equations system and is solved under given initial and boundary conditions in an iterative fashion. From the simulation results, we confirm that state variables show different behavior in the transient state; e.g., the velocity distribution in the flow field changes more quickly the linear density distribution. During a transient flow in a drafting zone, the output irregularity is influenced differently by the disturbances, e.g., the variation in input bundle thickness, the drafting speed, and the draft ratio.

• Journal of Korean Academy of Nursing
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• v.47 no.1
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• pp.133-141
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• 2017

Purpose: The aim of this study was to identify the relationship between awareness of nutrition labeling and menstrual cycle irregularity in women from a nationally representative sample of the Korean population. Methods: A cross-sectional analysis was performed using hierarchical multi-variable logistic regression analysis models. A total of 4,324 women aged 19~54 years from the 2010~2012 Korean National Health and Nutrition Examination Survey participated in the study. The participants were classified into three groups based on self-report responses to a questionnaire about their awareness of nutrition labels: Reading, Not-Reading, and Not-Knowing Groups. Results: The Reading, Not-Reading, and Not-Knowing Groups comprised 46.4%, 44.9%, and 8.7% of the participants, respectively, and 53.6% of the participants had never used nutrition labels. In the Not-Knowing Group, irregular menstrual cycles for more than 3 months were significantly more common than women with irregular menstrual cycles for up to 3 months and women with regular menstrual cycles. Women in the Not-Knowing Group were more likely to exhibit menstrual cycle irregularity (adjusted odds ratio: 1.63, 95% confidence interval: 1.10~2.41) compared to women in the Reading Group after adjusting for age, body mass index, smoking status, alcohol intake, exercise regularity, stress, depression, suicidal ideation, metabolic syndrome, age at menarche, parity, and use of oral contraceptives. Conclusion: No awareness of nutrition labeling appears to be associated with a higher prevalence of menstrual cycle irregularity in a nationally representative group of Korean women.

• Journal of the Korean Society for Railway
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• v.13 no.3
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• pp.304-308
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• 2010

This paper presents a methodology for identifying track irregularity using a wavelet transfer function. An equivalent wavelet SISO (single-input single-output) transfer function is defined by the measured track geometry and the acceleration data measured at a bogie of a train. All the measured data with various sampling frequencies were rearranged according to the constant 25cm reference recording distance of the track recording vehicle used in the field. Before applying the wavelet transform, measured data were regressed by eliminating those out of the range. The inverse wavelet transfer function is also formulated to estimate track geometry. The closeness of the estimated track geometry to the actual one is evaluated by the coherence function and also by FRF (frequency response function). A track irregularity index is defined by comparing the variance of the estimation error from the intact condition and that from the current condition. A simulation study has been carried out to examine the proposed algorithm.

• Korean Journal of Community Nutrition
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• v.8 no.5
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• pp.699-707
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• 2003

This study examined the effectiveness of two commonly used dietary assessment methods (the 24-hour recall and the food frequency questionnaire) in the epidemiological investigations of health-related habits and degenerative diseases. This cross sectional project in the Seoul area was conducted for the purpose of establishing cohort subjects and collecting reliable nutrient intake data for a further large-scale cross sectional study. The subjects were 91 volunteers from the Seoul area with a mean age of 53.5 \pm 9.6 for the males and 52.2 \pm 8.9 for the females. The subjects had a relatively high educational background, were from high socioeconomic levels, and were greatly concerned about healthrelated life styles. There was a significantly negative correlation between their smoking and their nutrient intake. Their drinking habits, their self-estimated health status and their concern or stress about being healthy did not have any influence on their nutrient intakes. Skipping meals was the most undesirable dietary habit influencing their nutrient intakes, and the next was their irregularity of eating meals. The subjects who liked legumes and fish had higher intakes of iron and niacin and those who liked milk and dairy products had higher intakes of calcium, vitamin \B_2 and fat. The subjects who considered themselves not to be healthy consumed higher amounts of fish and shell-fish, and those who considered themselves to be healthy consumed higher amounts of vegetables. The smokers consumed less fruits than non-smokers, but there was no correlation between their drinking and consumption of the food groups. There was no correlation between their food consumption frequency and their skipping meals or meal irregularity. There were positive correlations between their food likes and food consumption frequency for foods such as meat, milk and dairy products, seaweeds and fruits. Therefore, their smoking, skipping meals and meal irregularity appeared to greatly influence their nutrient intakes. Significant correlations were found between their health-related habits and their food group preferences and food frequencies. This implies that simple surveying methods using criteria such as smoking, skipping meals and meal irregularity, food group preferences and eating frequencies can be used as useful tools in the assessment of nutritional statuses.

• The Journal of the Convergence on Culture Technology
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• v.5 no.4
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• pp.401-406
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• 2019

The three-dimensional precision numerical analysis was performed using the finite element model applied with the railway track model consisting of rails, sleepers, and track elastic springs(ballast, rail pad). As a result of analyzing the track deformation level of the existing tracks due to the excavation work adjacent to the railway facilities, it was found that the track irregularity evaluation criteria (allowed values) of both conventional and high-speed railways lines were satisfied. Based on the numerical analysis using the track model, it was analyzed that the results of the prediction of the track irregularity due to the excavation work and the level of the track deformation occurring at the actual site could be approximated as closely as possible.

• Structural Engineering and Mechanics
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• v.82 no.1
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• pp.1-16
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• 2022

This work elaborately investigates the influences of the guideway geometry parameters and track irregularity on the dynamic performances of the suspended monorail vehicle-guideway system (SMVGS). Firstly, a spatial dynamic analysis model of the SMVGS is established by adopting ANSYS parameter design language. Then, the dynamic interaction between a vehicle with maximum design load and guideway is investigated by numerical simulation and field tests, revealing the vehicle-guideway dynamic features. Subsequently, the influences of the guideway geometry parameters and track irregularity on the dynamic performances of the SMVGS are analyzed and discussed in detail, and the reasonable ranges of several key geometry parameters of the guideway are also obtained. Results show that the vehicle-guideway dynamic responses change nonlinearly with an increase of the guideway span, and especially the guideway dynamic performances can be effectively improved by reducing the guideway span; based on a comprehensive consideration of all performance indices of the SMVGS, the deflection-span ratio of the suspended monorail guideway is finally recommended to be 1/1054~1/868. The train load could cause a large bending deformation of the pier, which would intensify the car-body lateral displacement and decrease the vehicle riding comfort; to well limit the bending deformation of the pier, its cross-section dimension is suggested to be more than 0.8 m×0.8 m. The addition of the track irregularity amplitude has small influences on the displacements and stress of the guideway; however, it would significantly increase the vehicle-guideway vibrations and rate of load reduction of the driving tyre.