• 제목/요약/키워드: cross sectional method

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Al-Mg 합금 박막의 압축응력 완화를 위한 어닐링 공정상의 입자 발달 (Evolution of grains to relieve additional compressive stress developed in Al-Mg alloy films during thermal annealing)

  • 이준성;양지훈;정재인;정용화;곽영진;김상섭
    • 한국표면공학회:학술대회논문집
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    • 한국표면공학회 2014년도 추계학술대회 논문집
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    • pp.47-51
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    • 2014
  • In this work, a possible mechanism for grain evolution in Al-Mg alloy films during thermal annealing is suggested on the basis of the phase transition and the related residual stress. Al-Mg alloy films with compositions of 14.0 and 18.0 wt% Mg content were deposited on cold-rolled steel substrates by the direct current co-sputtering method using Al and Mg targets. After the deposition, the samples were thermally annealed at $400^{\circ}C$ for 10 min. The featureless, dense cross-sectional microstructure of the as-deposited films turned into a grainy microstructure after the thermal annealing. According to the residual stress evaluated by using the $XRD-sin2{\psi}$ technique and the phase analysis by XRD, it is likely that grains were created in order to relieve the additional accumulation of residual stress originating from the phase transition from face-centered cubic Al (${\alpha}$) to Al3Mg2 (${\beta}$) and Mg (${\delta}$) phases, suggesting interplay between the microstructure and residual stress.

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소의 늑골에서 탈회정도와 노출시간에 따른 프랙탈 차원의 변화 (Change of the fractal dimension according to the decalcification degree and the exposure time in the bovine rib)

  • 정연화;나경수;조봉혜
    • Imaging Science in Dentistry
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    • 제36권2호
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    • pp.69-72
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    • 2006
  • Purpose : We evaluated the fractal dimension changes on bovine rib radiographs according to the decalcification degree and the exposure time in the bovine rib. Materials and Methods : Twenty 5 mm thick cross-sectional blocks from bovine rib bone were progressively decalcified in 30 mL 0.1 N hydrochloric acid for 5, 30, and 90 minutes. They were radiographed at three exposure time settings (0.22, 0.36, 0.43 mAs) before and after each decalcification stage. We selected $100{\times}100$ pixel-sized regions of interests (ROIs) on trabecular bone and calculated fractal dimensions by box-counting method. Results : Repeated measures ANOVA showed that fractal dimensions gradually decreased after acid-induced demineralization and with more exposure (P<0.001). Conclusion : The fact that fractal dimensions decrease after decalcification might support the hypothesis that patients with osteoporosis have decreased radiographic fractal dimension in trabecular bone in comparison to normal subjects.

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간호대학생의 캥거루 돌보기에 대한 지식과 신념 (Knowledge and Beliefs about Kangaroo Care among Nursing Students)

  • 박소영;구상미;최선미;김태임
    • Child Health Nursing Research
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    • 제22권1호
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    • pp.61-69
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    • 2016
  • Purpose: This study was conducted to investigate nursing students' knowledge and beliefs about Kangaroo care (KC). Methods: A cross-sectional descriptive design was used. Undergraduate students enrolled in departments of nursing (n=322) from three universities in D city participated. Knowledge and beliefs about KC were measured using the Kangaroo Care Questionnaire (KCQ). Results: The overall level of nursing students' knowledge about KC was very low with a mean score of 6.9 out of 17. The mean score for nursing students' beliefs about KC was 87.4 out of 100, indicating relatively positive beliefs. The students who had both education and exposure to KC had higher scores for knowledge and more positive beliefs about KC compared to students with no experience or exposure to KC. There was a positive correlation between knowledge and beliefs about KC (r=.371, p<.001). Conclusion: The results suggest that there is a need to develop educational programs for nursing students in order to increase their knowledge and develop positive beliefs about KC.

학령전기와 학령기 아동에서의 아토피 피부염 유병률과 위험인자 (Prevalence and Risk Factors for Atopic Dermatitis in Pre-school and School Aged Children)

  • 이윤미;황선욱
    • Child Health Nursing Research
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    • 제14권3호
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    • pp.285-294
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    • 2008
  • Purpose: This study was done to estimate the prevalence of atopic dermatitis (AD) and its risk factors for AD in children living in the community. Method: Random samples of 10,236 were selected from 43 kindergarten (1,418) and 57 elementary (8,718) students in K city. Data from 1,079 (kindergarten children) and 7,271 (elementary) students were used in the final analysis. The Korean-translated modified version of the International Study of Asthma and Allergies in Childhood (ISSAC) questionnaire was used in this cross-sectional survey. Parents answered the survey questionnaire. Results: The lifetime and last 12-month prevalence of AD were 40.15%; 30.86% in kindergarten children and 33.56%; 25.37% in elementary children. The lifetime and last 12-month prevalence of AD diagnosis were 40.8%; 18.68% in kindergarten children and 34.36%; 12.63% in elementary children. The lifetime prevalence of AD treatment was 25.93% in kindergarten children and 22.07% in elementary children. Multivariate logistic regression analysis revealed that risk factors for AD were age, allergic disease, age of house, carpets, pets. Conclusion: The study suggests that prevalence of AD has increased among children in the community. These data can be used to manage possible risk factors that are predictors of childhood AD.

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Blood glucose levels, insulin concentrations, and insulin resistance in healthy women and women with premenstrual syndrome: a comparative study

  • Zarei, Safar;Mosalanejad, Leili;Ghobadifar, Mohamed Amin
    • Clinical and Experimental Reproductive Medicine
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    • 제40권2호
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    • pp.76-82
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    • 2013
  • Objective: To compare the blood glucose levels, insulin concentrations, and insulin resistance during the two phases of the menstrual cycle between healthy women and patients with premenstrual syndrome (PMS). Methods: From January of 2011 to the August of 2012, a descriptive cross-sectional study was performed among students in the School of Medicine of Jahrom University of Medical Sciences. We included 30 students with the most severe symptoms of PMS and 30 age frequency-matched healthy controls. We analyzed the serum concentrations of glucose, insulin, and insulin resistance by using the glucose oxidase method, radioimmunometric assay, and homeostasis model assessment of insulin resistance equation, respectively. Results: No significant differences between the demographic data of the control and PMS groups were observed. The mean concentrations of glucose of the two study groups were significantly different during the follicular and luteal phases (p=0.011 vs. p<0.0001, respectively). The amounts of homeostasis model assessment of insulin resistance of the two study groups were significantly different in the luteal phase (p=0.0005). Conclusion: The level of blood glucose and insulin resistance was lower during the two phases of the menstrual cycle of the PMS group than that of the controls.

Behaviour and design of composite beams subjected to flexure and axial load

  • Kirkland, Brendan;Uy, Brian
    • Steel and Composite Structures
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    • 제19권3호
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    • pp.615-633
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    • 2015
  • Composite steel-concrete beams are used frequently in situations where axial forces are introduced. Some examples include the use in cable-stayed bridges or inclined members in stadia and bridge approach spans. In these situations, the beam may be subjected to any combination of flexure and axial load. However, modern steel and composite construction codes currently do not address the effects of these combined actions. This study presents an analysis of composite beams subjected to combined loadings. An analytical model is developed based on a cross-sectional analysis method using a strategy of successive iterations. Results derived from the model show an excellent agreement with existing experimental results. A parametric study is conducted to investigate the effect of axial load on the flexural strength of composite beams. The parametric study is then extended to a number of section sizes and employs various degrees of shear connection. Design models are proposed for estimating the flexural strength of an axially loaded member with full and partial shear connection.

연변 거주 중국인 대상자를 통해 살펴본 체질 진단툴(Sasang Constitutional Analysis Tool)의 해외 적용 가능성 탐색 연구 (The Preliminary Study on the Possibility of Applying Sasang Constitutional Analysis Tool to Foreign Site based on Yanbian Chinese)

  • 유종향;김윤영;도준형;박기현;장은수
    • 사상체질면역의학회지
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    • 제24권3호
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    • pp.42-49
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    • 2012
  • Objectives This study aimed to assessing the performance of Sasang constitutional analysis Tool (SCAT) for Chinese as one of method to diagnose Sasang Constitution and evaluating the possibility of applying SCAT to foreign people. Methods This cross-sectional study was approved by IRB (Independent Review Board) at J Hospital in Yanbian. Informed consent to take part in the study was obtained from each of the participants. The performance of SCAT was assessed through Kappa coefficient and the concordance rate between SCAT and expert diagnosis. Results The concordance rate between SCAT and expert was 61.1% in total and the Kappa was 0.408. When the constitutional probability increased, the concordance rate and Kappa showed a increasing tendency. The concordance rate of Chosun race was 62.1% and others 60.7%. Conclusions SCAT, as Sasang constitutional diagnostic supporting system, may help the expert to diagnose Sasang constitution in Yanbian region.

단면 윤곽선을 기반으로 한 두부표변의 재구성 (Reconstruction of Head Surface based on Cross Sectional Contours)

  • 한영환;성현경;홍승홍
    • 대한의용생체공학회:의공학회지
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    • 제18권4호
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    • pp.365-373
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    • 1997
  • 본 논문에는 표면 형태만을 고려한 방법으로 다수의 단면 영상 데이터로부터, 관심있는 기관의 외부 표면을 패치(patch)에 의한 방법으로 재구성하여 삼차원적으로 표시하는 것을 목적으로 한다. 이를 위해 본 논문에서는 표면을 형성하기 위한 특징점을 추출하기 위하여 제거법에 의한 특징점 추출이라는 알고리즘을 제안하여 사용하였으며, 표면을 재구성하기 윟나 과정에서 두 단면의 영상의 특징점 사이의 최소 거리를 비용 함수로 사용하는 방법을 제안하였다. 제안한 알고리즘의 효용성을 확인하기 위하여 두부에 대한 이차원 CT 영상을 사용하여 실험을 실시하고 다른 방법과 비교하여 보았다.

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Sn58Bi Solder Interconnection for Low-Temperature Flex-on-Flex Bonding

  • Lee, Haksun;Choi, Kwang-Seong;Eom, Yong-Sung;Bae, Hyun-Cheol;Lee, Jin Ho
    • ETRI Journal
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    • 제38권6호
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    • pp.1163-1171
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    • 2016
  • Integration technologies involving flexible substrates are receiving significant attention owing the appearance of new products regarding wearable and Internet of Things technologies. There has been a continuous demand from the industry for a reliable bonding method applicable to a low-temperature process and flexible substrates. Up to now, however, an anisotropic conductive film (ACF) has been predominantly used in applications involving flexible substrates; we therefore suggest low-temperature lead-free soldering and bonding processes as a possible alternative for flex-on-flex applications. Test vehicles were designed on polyimide flexible substrates (FPCBs) to measure the contact resistances. Solder bumping was carried out using a solder-on-pad process with Solder Bump Maker based on Sn58Bi for low-temperature applications. In addition, thermocompression bonding of FPCBs was successfully demonstrated within the temperature of $150^{\circ}C$ using a newly developed fluxing underfill material with fluxing and curing capabilities at low temperature. The same FPCBs were bonded using commercially available ACFs in order to compare the joint properties with those of a joint formed using solder and an underfill. Both of the interconnections formed with Sn58Bi and ACF were examined through a contact resistance measurement, an $85^{\circ}C$ and 85% reliability test, and an SEM cross-sectional analysis.

학령전기와 학령기 아동의 천식 유병률과 위험인자 (Prevalence and Risk Factors of Asthma in Community Childhood)

  • 이윤미;김병수
    • Journal of Korean Biological Nursing Science
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    • 제10권1호
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    • pp.53-61
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    • 2008
  • Purpose: This study was conducted to estimate the prevalence of asthma and its risk factors in childhood asthma. Method: Random samples of 10,236 were selected from 43 kindergarten (1,418) and 57 elementary (8,718) in K city between september and November (2007). 1,079 (kindergarten children) and 7,271 (elementary children) were in the final analysis. The Korean-translated modified version of the questionnaire for the International Study of Asthma and Allergies in Childhood was used in this cross-sectional survey. Parents were surveyed to answer for the questionnaire. Result: The lifetime and 12-month prevalence of wheezing were 11.50%; 11.06% in kindergarten children and 19.24%; 4.80% in elementary children. The lifetime prevalence of asthma diagnosis and the 12-month prevalence of asthma treatment were 11.59%; 4.43% in kindergarten children and 4.43%; 10.78% in elementary children. The 12-month prevalence of night cough and exercise-induced wheezing were 12.90%; 3.33% in kindergarten children and 20.72%; 4.74% in elementary children. Risk factors analysis showed that age, paternal and maternal asthma, allergic disease, carpet use, monthly income, indoor environment were associated with a higher risk of asthma. Conclusion: The study suggests that prevalence of asthma has increased among the community children. These data have been used to manage a possible role of risk factors as predictors of childhood asthma.

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