• Wind and Structures
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• v.16 no.6
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• pp.617-627
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• 2013

In wind load calculations based on pressure measurements, the concept of 'tributary area' is usually used. The literature has less guidance for a systematic computational methodology for calculating tributary areas, in general, and for scattered pressure taps, in particular. To the best of the author's knowledge, there is no generic mathematical equation that helps calculate the tributary areas for irregular pressure taps. Traditionally, the drawing of tributary boundaries for scattered and intensively distributed taps may not be feasible (a time and resource consuming task). To alleviate this problem, this paper presents a proposed numerical approach for tributary area calculations on rectangular surfaces. The approach makes use of the available coordinates of the pressure taps and the dimensions of the surface. The proposed technique is illustrated by two application examples: first, quasi-regularly distributed pressure taps, and second, taps that have scattered distribution on a rectangular surface. The accuracy and the efficacy of the approach are assessed, and a comparison with a traditional method is presented.

• Proceedings of the KSR Conference
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• 2003.10a
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• pp.181-186
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• 2003

In order to develop a high speed train, various conditions have been considered. Fatigue strength assessment by the fluctuation of pressure is an important one. In this study, a numerical simulation has been performed to estimate the fluctuation and frequency of pressure when KHST(Korean High Speed Train)passes through tunnels in the Kyung-Bu high-speed railway. The simulation was based on KHST running the Kyung-Bu high-speed line with the speed of 350km/h and the interval of 10 minute headway. And the tunnel entrance speed was estimated by TPS program. Therefore, the fluctuation and frequency of pressure is expressed in Weibull distribution function in the above running situation. The result in this study would be good guidance to calculate the fatigue life and the index of reliability of body structure. We are going to conduct more study to measure the real value of the pressure of the carbody passing through tunnels, to assess the fatigue reliability and to develop method ＆ procedure for the fatigue reliability design.

• Proceedings of the Korea Water Resources Association Conference
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• 2002.05b
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• pp.1195-1204
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• 2002

The impacts of El Nino Southern Oscillation (ENSO) phenomenon on climate are widespread and extend far beyond the tropical Pacific. The phenomenon can be characterized by Southern Oscillation Index (SOI) which is derived from values of the monthly mean sea level pressure barometric difference between Tahiti and Darwin, Australia. Its best-known extreme is the El Nino event. In this study, general statistical characteristics of SOI and the data from which it is derived (i.e. mean sea level pressure data at Tahiti and Darwin) are presented as guidance when using SOI far other analyses. The characteristics include the availability of the barometric pressure data, statistics of monthly pressure data, correlation of SO intensity, frequency analysis of SOI by magnitude and by month (January-December), duration properties of SOI by run analysis.

• Journal of Korean Public Health Nursing
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• v.18 no.2
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• pp.312-329
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• 2004

This study was examined 718 workers who had consistent blood pressure results in 2001 and 2002 general health examinations that were held at a work places managed by a health care agency in Seoul. Significant results are found as follows by analysing SPSS 11.0 on the result of self-recorded questionnaires investigated from Mar 1, 2003 to April 30, 2003. 1. A sampled healthy group and a sampled unhealthy group had significant differences in four variables out of possible nineteens that are sex, age, marriage and occupation. The unhealthy group had more males than females, more aged (over 50 years old) than youngers (under 50 years old), more married than singles, more manufacturing workers than non-manufacturing workers. In the case of systolic blood pressure, as the healthy group had 16.52mmHg while that of the other group had 149. 58mmHg, 33.06mmHg of difference between those groups were detected. In the case of diastolic blood pressure, 74.93mmHg of the healthy group and 96.53mmHg of the unhealthy group yielded 21.60mmHg of difference between them. This result implies that a guidance of health care is required to be aware of 20-30mmHg volatility in blood pressure rate or to understand and treat properly own blood pressure. as it is difficult to detect hypertension in early stage due to no initial symptom. According to the result. an establishment of management system of workers, companies and health care agencies is required for consist health care. 2. In terms of risky habits to health, the unhealthy group had more proportion of past smokers, over-twice-a-week drinkers, people with higher obesity rate. However, in terms of excercise, the proportion of regularly exercising people is higher in the unhealthy group while that of non-exercising people is higher in the healthy group. On the other hand. the average grade of health practicing behaviour in two groups are not significantly different as the health group had 3.00 out of possible 6.00 while the other had 3.10. This result means that as workers are not interested in health practicing behaviour. health promoting programmes must be developed in such a way of various method of motivations and incentives. Particularly this implies that distortional objectives of exercises should be readjusted through health guidance. 3. Systolic blood pressure in the healthy group can be explained by sex and the obesity rate while that in the unhealthy group can be explained by subjective health awareness and the obesity. Diastolic blood pressure in the healthy group can be explained by sex and the obesity rate like the former. The obesity rate was significant variable affecting the blood pressure of both groups, and particularly the effect to the unhealthy group was remarkably higher than that to the healthy group. Therefore, this research identified that the health care on the blood pressure of workers is not only limited to hypertension patients, but also extended to all workers. In order for consistent care, an establishment of management system of workers, companies and health care agencies is required.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.19 no.4
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• pp.36-44
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• 2020

This study analyzed the deformation behavior of the high density polyethylene (HDPE) bottle in the blow molding process. We carried out finite element (FE) simulations using ANSYS Polyflow. First, the axisymmetric model was executed by 2D FE-simulation to determine the change of bottle wall thickness during the molding process. Then, the square model of the bottle was executed by 3D FE-simulation to gauge the effects of gas pressure on the change of wall thickness. The experiment results showed that the FE-simulations were able to upgrade the quality of the HDPE bottle in the blow molding process. These results can be used as guidance in adjusting gas pressure, as well as be extended for further study to determine process parameters such as temperatures, forming velocity, parison shape, etc.

• Korean Journal of Occupational Health Nursing
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• v.9 no.1
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• pp.56-61
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• 2000

This study was done in an attempt to reveal those factors interfering with the observation study. Three trained research assistants collected data by observing the two occupational health nurses working in the small scale enterprises on the 3rd and 10th of February, 1999. The first observation was performed on the 3rd of February without observation guidance. Guidance was given during the second observation on the 10th of February. These data were compared between reporters in nursing services of 'Workplace visiting', 'Health counselling' and 'Blood pressure checking' according to nursing time and frequency. These areas were chosen because these activities were regarded as clearly identifiable by observers in contrast to the other performances. The data showed inconsistency between reporters. However, they were reduced when reporters observed nurses with guidance, although there were still minor differences between data in time and frequency. Discussions were carried out to find possible reasons for these differences. The causes were mainly attributed to the difficulty in workplace conditions to observe, the work specificity of nurses visiting each workplace and the delicate situation between nurses and observers when reporters were travelling in the nurse's car. Therefore, the results suggest that the observation method applied to the nursing service research at small-scale enterprises should be more concerned about the selection of appropriate workplace and operational definition of nursing activity in order to more precisely measure nurses' attitudes.

• Korean Journal of Human Ecology
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• v.12 no.3
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• pp.287-301
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• 2003

The purpose of this study was to explore the relationship between childrearing belief and parental efficacy of women before and after childbirth. For this purpose 253 pregnant women and 256 mothers with infants under one year of age were contacted and asked to fill in a packet of survey questionnaire at their visits to obstetrician, gynecologist and pediatrician. The questionnaire includes questions about what mothers value in childrearing, their expectations for their children and parental efficacy. Data collected were analyzed using SAS PC program. It was reported that comparing to mothers, pregnant women view childrearing in more ideal lights and expect their children to be more exceptional. Also working mothers reported comparatively lower parental efficacy than full-time mothers suggesting that social support system to minimize pressure coming from work for working mothers with young children should be provided and the parental education methods to enhance the parental efficacy should be sought.

• International Journal of Railway
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• v.2 no.2
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• pp.93-97
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• 2009

The experiments for aerodynamic characteristics of railway acoustic screen are performed using 1/61 scaled-down moving model rig facility which employs an axis symmetry and one wire guidance method. The launching mechanism is an air-gun type. The train model for the experiment is the high speed train (Korea Train Express: KTX) and the tested speed is about 300 km/h. The tested train length is 61 em which is corresponding to two units of KTX train. The cross sectional area and weight of train model are 0.00264 $m^2$ and 287 g, respectively. The Reynolds number based on the model train length is $1.2{\times}10^7$. The strength of pressure wave is measured using piezo typed pressure sensor. The measured pick value of pressure was as high as 365 Pa in the shortest gap between the acoustic screen and model train. The measured pressure is well compared with the field test data of mc 779-1 [2] values. However, the experimental data were slightly lower than the mc 779-1 values. The results show the model test can be used as a substitute for the field test.

• Journal of the Korean Society of Tobacco Science
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• v.22 no.2
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• pp.151-156
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• 2000

The variability of a ventilated filter cigarette depends on the details of its construction and on the variabilities of its components. Variations in filter ventilation arise from many sources, including variations in tobacco rod pressure drop, filter tip pressure drop, tipping paper permeability, and plugwrap permeability. To reduce the filter ventilation variability, the variability of filter ventilation levels in ventilated cigarettes is studied by Monte Carlo Analysis. For each trials a value is selected for tobacco rod pressure drop, filter tip pressure drop, tipping paper permeability, and plugwrap permeability. These values are selected randomly from a normal distribution based on the target and coefficient of variation for each input variable. The results of this analysis for filter ventilation variation suggest that the variations of filter ventilation are dependent on the details of cigarette designs studied and reducing the variability of any cigarette component will reduce filter ventilation variability. For typical cigarettes, variation in the permeability of tipping paper is usually the most significant contributor to filter ventilation variability. Results of a Monte Carlo Analysis could provide both general insights and specific practical guidance about the design of ventilated filter cigarettes.

• Proceedings of the KSR Conference
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• 2004.06a
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• pp.853-858
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• 2004

In order to develop a high speed train, various conditions have been considered. Fatigue strength assessment by the fluctuation of pressure is an important one. When high speed train passing though tunnels, the pressure wave is generated in tunnels and pressure variation by the wave is acting on carbody structure with dynamic load repeatedly. In this study, formulation for reliability based fatigue assessment method has been performed when the high speed train passes through tunnels. The formulation was based on structural reliability index method and followed the proposed ISO method. The result by this study would be a good guidance to calculate the fatigue life and reliability index of body structure.