• Title/Summary/Keyword: cross-sectional dependence

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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.

A NEW MEASUREMENT METHOD OF FEMORAL ANTEVERSION BASED ON THREE DIMENSIONAL MODELING (3차원 모델링을 이용한 대퇴 전염각의 측정)

  • Kim, June-S.;Park, Hee-J.;Choi, Kwang-S.;Choi, Kui-W.;Kim, Sun-I.
    • Proceedings of the KOSOMBE Conference
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    • v.1997 no.05
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    • pp.141-144
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    • 1997
  • Femoral neck anteversion is the angle between the neck and the knee axis projected on a plane perpendicular to the longitudinal axis. Conventional methods that use cross-sectional Computed Tomography(CT) images to estimate femoral anteversion have several problems because of the complex 3D structure of the femur. These are the ambiguity of defining the longitudinal axis, the femoral neck axis and condylar line, and the dependence on patient positioning. Especially the femoral neck axis that is known as a major source of error is hard to determine from a single or multiple 2D transverse images. So we developed a new method for measuring femoral anteversion by 3D modeling method. In this method, femoral head is modeled as a sphere. The center of femoral neck is the mid-point of the 2D reconstructed oblique image in the femoral neck part. Then neck axis is a line connecting foregoing two centers. We model the longitude of femur as a cylinder, and the long axis is defined from the fitted cylinder. The knee axis which is tangent to the back of the femoral condyles is easily determined by table-top method. By the definition of femoral anteversion, the femoral anteversion is easily calculated from this model.

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Age Specific Cytological Abnormalities in Women Screened for Cervical Cancer in the Emirate of Abu Dhabi

  • Al Zaabi, Muna;Al Muqbali, Shaikha;Al Sayadi, Thekra;Al Ameeri, Suhaila;Coetsee, Karin;Balayah, Zuhur;Ortashi, Osman
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.15
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    • pp.6375-6379
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    • 2015
  • Background: Cervical cancer is the second most common cancer in women worldwide, with about 500,000 new cases and 270,000 deaths each year. Globally, it is estimated that over one million women currently have cervical cancer, most of whom have not been diagnosed, or have no access to treatment that could cure them or prolong their lives. In the United Arab Emirates (UAE) cervical cancer is the third most common cancer in women. Materials and Methods: A population-based cross-sectional retrospective survey of cervical smear abnormalities was conducted in the Emirate of Abu Dhabi, UAE, from January 2013 to December 2013 by collecting consecutive liquid-based cytology samples from the Department of Pathology at the SKMC Hospital in Abu Dhabi city. Results: The total number of women screened for cervical cancer for the year 2013 at SKMC was 4,593, with 225 (4.89%) abnormal smears. The majority of the abnormal smear results were atypical squamous cells of undetermined significance (ASCUS) 114 (2.48%). This study showed 60% increase in the rate of abnormal cervical smears in the UAE over the last 10 years. In this study the highest incidence of high grade abnormalities were seen in women above the age of 61years (1.73%), this might be due to the fact that this group of women missed the chance of screening of cervical cancer earlier in their lives or could be explained by the well-known second peak of HPV infection seen in many prevalence studies. Conclusions: We conclude that the rate of abnormal cervical smear in the screened Abu Dhabi women is not different from the rate in developed countries. A notable increase in both low and high grade abnormalities has occurred within the last decade.

Subjective and Objective Caregiver Burden in Parkinson's Disease

  • Kim, Keum-Soon;Kim, Bog-Ja;Kim, Kyung-Hee;Choe, Myoung-Ae;Yi, Myung-Sun;Hah, Yang-Sook;Chung, Sun-Ju;Kwon, So-Hi
    • Journal of Korean Academy of Nursing
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    • v.37 no.2
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    • pp.242-248
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    • 2007
  • Purpose. Parkinson's disease (PD) is a common neurodegenerative disorder characterized by motor disabilities and increasing dependence on others for daily life activities with consequent impact on patients' and caregivers' quality of life. The aim of this study was to elucidate the burden on primary caregivers of patients with PD, and identify related factors. Methods. A cross-sectional descriptive study. Seventy-six primary caregivers of PD patients in a neurology out-patient clinic, Seoul, Korea completed structured questionnaires, of which 68 were analyzed. The structured self-report questionnaire included (1) demographic information on the caregivers, (2) information regarding the disease characteristics of the patients, and (3) the subjective and objective caregiver burdens as assessed on Montgomery, Gonyea, & Hooyman's scale. Results. The mean age of the caregivers was 54.56 years, and spouses represented the largest proportion (47.0%). Caregivers of PD patients experienced high levels of burden (mean scores on the subjective and objective burdens were 45.22 and 34.90, respectively), which were comparable to the caregiver burdens in stroke, and higher than the caregiver burdens in general chronic disease. Older caregivers and spousal caregivers experienced significantly higher burdens (p=.004 and p=.019, respectively). A greater motor disability and higher modified Hoehn and Yahr grade were related to higher caregiver burden (p=.001 and p=.018, respectively). Conclusion. Caring for PD patients is associated with a high level of caregiver burden. Therefore, healthcare professionals should identify the burden of caregivers who look after PD patients and develop comprehensive management strategies both for patients and their caregivers.

School Teachers' Health Behaviors and Health Status in Seoul and Gyeonggi-do (서울 경기 지역 교사의 건강행동과 건강상태)

  • Lee, Eun-Young;Choi, Bo-Youl;Sohn, Ae-Ree;Ahn, Dong-Hyun
    • Korean Journal of Health Education and Promotion
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    • v.26 no.4
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    • pp.49-62
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    • 2009
  • Objectives: Few studies have focused on health behaviors and health status among teachers even though these are one of principles and values of WHO's Health Promoting Schools. In this study, we described health behaviors and health status among teachers and explored the differences of these by personal and school characteristics. Methods: A stratified and random cluster sampling design was used to obtain a cross-sectional sample. A total of 59 elementary, middle and high schools in Seoul and Gyeonggi areas were included in which 333 teachers (males 40.6%, females 59.4%) participated in this survey. Chi-square tests were conducted with SPSS 17.1. Results: Overall, health behaviors and health status among teachers were better than the general public according to Korea National Health and Nutrition Examination Survey. Male and middle/high school teachers had higher prevalence of alcohol dependence and of driving under the influence of alcohol. Also, their rate of wearing seat belts were lower compare to female. In other hand, female, health and nutrition teachers, rural school teachers had lower prevalence of meeting recommended levels of physical activity. Underweight were more prevalent to them in contrast to male with higher prevalence of obesity. In addition, teachers of health promoting schools were not likely to ride on a car with a drunk driver. They also have a lower prevalence of skipping breakfast and have higher positive perception of health for themselves. Conclusion: Teachers' health should be given higher concerns as a key component of school based health promotion. Gender and age specific programs should be considered to develop health promoting programs for them.

Predictive Factors of Aspects of the Transtheoretical Model on Smoking Cessation in a Rural Community (범이론 모형을 기초로 한 농촌지역 성인의 금연행위에 영향을 미치는 요인)

  • Ahn Ok-Hee;Yeun Eunja;Kwon Sung-Bok;Chung Hae-Kyung;Ryu Eunjung
    • Journal of Korean Academy of Nursing
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    • v.35 no.7
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    • pp.1285-1294
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    • 2005
  • Purpose: This study was done to evaluate the predictive value of aspects of the Transtheoretical model (TTM) of behavior change as applied to smoking cessation in a rural population. Method: A convenience sample was recruited from a public health center in a community. A total of 484 participants were recruited, including 319 smokers, 116 ex-smokers and 49 non-smokers. A cross-sectional and descriptive design was used in this study. Data was analyzed using descriptive statistics, frequency statistics, ANOVA and Logistic regression. Result: The major findings were 1) The participants were assessed at baseline for their current Stage of Change resulting in a distribution with $42.1\%$ in Precontemplation, $24.1\%$ in Contemplation, $9.7\%$ in Preparation, $6.2\%$ in Active, and $17.9\%$ in the Maintenance stage. 2) There were statistically significant differences of processes of change, decisional balance and situational temptation across the stages of change. 3) The main factors that affect smoking cessation were age, number of years smoking, age when began smoking, self-liberation and negative/affective situations, which combined explained $33.2\%$ of the smoking cessation. Conclusion: TTM variables measured prior to a smoking cessation program added little predictive value for cessation outcome beyond that explained by demographic and smoking history variables.

Effect of Plasma Oxidation lime on TMR Devices of CoFe/AlO/CoFe/NiFe Structure (절연막층의 플라즈마 산화시간에 따른 CoFe/AlO/CoFe/NiFe 구조의 터널자기저항 효과 연구)

  • 이영민;송오성
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.15 no.4
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    • pp.373-379
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    • 2002
  • We investigated the evolution of magnetoresistance and magnetic property of tunneling magnetoresistive(TMR) device with microstructure and plasma oxidation time. TMR devices have potential applications for non volatile MRAM and high density HDD reading head. We prepared the tunnel magnetoresistance(TMR) devices of Ta($50{\AA}$)/NiFe($50{\AA}$)/IrMn($150{\AA}$)/CoFe($50{\AA}$)/Al($13{\AA}$)-O/CoFe($40{\AA}$)/FiFe($400{\AA}$)/Ta(($50{\AA}$) structure which have $100{\times}100\mu\textrm{m}^2$ junction area on $2.5{\times}2.5\textrm{cm}^2$ Si/$SiO_2$(($1000{\AA}$) substrates by an inductively coupled plasma(ICP) magnetron sputter. We fabricated the insulating layer using an ICP plasma oxidation method by with various oxidation time from 30 sec to 360 sec, and measured resistances and magnetoresistance(MR) ratios of TMR devices. We found that the oxidized sample for oxidation time of 80 sec showed the highest MR radio of 30.31 %, while the calculated value regarding inhomogeneous current effect indicated 25.18 %. We used transmission electron microscope(TEM) to investigate microstructural evolution of insulating layer. Comparing the cross-sectional TEM images at oxidation time of 150 sec and 360 sec, we found that the thickness and thickness variation of 360 sec-oxidized insulating layer became 30% and 40% larger than those of 150 sec-oxidized layer, repectively. Therefore, our results imply that increase of thickness variation with oxidation time may be one of the major treasons of the MR decrease.

Demand and willing to pay for oral hygiene service in long-term care insurance of elderly (노인장기요양보험 재가급여 수급자의 구강위생서비스 요구도와 비용지불의사)

  • Kim, Han-Nah;Kim, Gi-Yon;Noh, Hie-Jin;Kim, Nam-Hee
    • Journal of Korean Academy of Oral Health
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    • v.42 no.4
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    • pp.204-209
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    • 2018
  • Objectives: This study was conducted to identify the demand and willingness to pay for oral hygiene services among elderly people with long-term care insurance. Methods: Our study was a cross-sectional analysis. Subjects comprised 126 elderly individuals from long-term home-care centers. A total of 28 centers were selected through convenience sampling from among 78 centers in ${\bigcirc}{\bigcirc}$. For analysis, semi-structured questionnaires that required about 20-30 minutes to complete were used. Analysis was performed using SPSS 23.0 software. Results: The overall demand for oral hygiene services was 44.4%, and willingness to pay was 31.0%. Thirty-three people (58.9%) of elderly those who have demand for an oral hygiene service were willing to pay for the service, and 64 people (91.4%) who did not have a demand were not willing to pay for it. Among those with partial dependence on brushing, 65.6% had demand for oral hygiene services and 50.0% were willing to pay costs. Among basic livelihood beneficiaries, 69.6% were willing to pay for oral hygiene services; general subjects and relievers were less willing to pay. Conclusions: The overall demand for oral hygiene services among elderly people was 44.4%, and the willingness to pay was as low as 31.0%.

An Analysis of Non-linear Relationship between Local Government Size and Regional Economic Growth: Armey Curve Verification Using AMG Estimation Method (지방정부규모와 지역경제성장 간 비선형관계 분석: AMG 추정법을 이용한 Armey Curve 검증)

  • So-youn Kim;Suyeol Ryu
    • Journal of the Economic Geographical Society of Korea
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    • v.25 no.4
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    • pp.629-640
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    • 2022
  • This study analyzed the relationship between local government size and regional economic growth using regional data from 2002 to 2020. By dividing local government expenditure into social development expenditure and economic development expenditure, economic growth and the inverted U-shaped Armey curve were verified, and the optimal size of local government expenditure was examined. In particular, the AMG estimation method considering the cross-sectional dependence and regional heterogeneity existing in the panel data was utilized. As a result of the analysis, it was found that there was an inverted U-shaped relationship between local fiscal expenditure and regional economic growth. When the proportion of total local fiscal expenditure is 7.63% of GRDP and social development expenditure is 3.45%, it is found that the optimal size of expenditure can maximize the regional economic growth rate. Local governments should increase the effectiveness of public expenditure policies by considering these points.

College Alcohol Study for Alcohol-Related Behaviors and Problems (우리나라 대학생의 음주행태 심층조사)

  • Ju, Yeong Jun;Oh, Sarah Soyeon;Park, Sang Ick;Lee, Hye-Ja;Yoo, Min-Gyu;Park, Eun-Cheol
    • Health Policy and Management
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    • v.29 no.1
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    • pp.58-67
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    • 2019
  • Background: In this study, we aimed to investigate the drinking behaviors and drinking-related problems of college students in South Korea to produce national alcohol statistics. Methods: We carefully examined the questionnaires and previous research developed in the previous research project and selected questions that reflect the special environment and culture of college students. In order to stratify a nationally representative sample of college students, the distribution of students around the country were found through the educational statistics database of the Korea Educational Development Institute. Based on this information, we conducted a survey in collaboration with Gallup (Korea) to survey and analyze the drinking behaviors of 5,024 Korean students. Results: A nationwide cross-sectional survey was conducted in 2017, for Korean college students. A total of 5,024 students were recruited and analyzed. The monthly drinking rate was 78.0% for male students and 72.9% for female students. The high-risk drinking rate was 23.3% for male students and 17.2% for female students. The most popular category for number of drinks per drinking session was 'more than 10 glasses' per drinking session for both male (44.1%) and female (32.8%). On the alcohol use disorders identification test, the greatest proportion of male students were in the high-risk drinking category (score 8 to 15) 43.8%, followed by the 'low-risk drinking' (score 0 to 7) in 43.6%, 'alcohol abuse' (score 16 to 19) 7.2%, and 'alcohol dependence' (greater than 20) 5.4% categories, respectively. For female students, the greatest proportion of female students were in the 'low-risk drinking' in 49.6%, followed by 'high-risk drinking' 37.1%, 'alcohol abuse' 8.4%, and 'alcohol dependence' 4.9% categories, respectively. Conclusion: The results of the study showed that the drinking behavior of Korean college students was excessive. Overall, it was found that the college population has a greater high-risk drinking behaviors than general adult population. Furthermore, these problem drinking behaviors were prominent among female college students. Results from the present study suggest that it is necessary to monitor the drinking behavior of college students with constant interest and to prepare policies and strategies suitable for these circumstances.