• Advances in nano research
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• 제8권1호
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• pp.13-24
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• 2020

In this paper, for the first time based on the nonlocal strain gradient theory the effect of size dependency in torsional vibration of bi-direction functionally graded (FG) nonlinear nano-cone is study. The material properties were assumed to vary according to the arbitrary function in radial and axial directions. The Navier equation and boundary conditions of the size-dependent bidirectional FG nonlinear nano-cone were derived by Hamilton's principle. These equations were solved by employing the generalized differential quadrature method (GDQM). The presented model can turn into the classical model if the material length scale parameters are taken to be zero. The effects of some parameters, such as inhomogeneity constant, cross-sectional area parameter and small-scale parameters, were studied. As an essential result of this study can be stated that an FG nano-cone model based on the nonlocal elasticity theory behaves softer and based on the strain gradient theory behaves harder.

• 한국산업융합학회 논문집
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• 제23권2_2호
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• pp.289-299
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• 2020

The composition of convergence cross-section of the material is a technique that provides reasonable design and construction of structures. It is frequently used in medium-sized bridges and architectural structures. However, the structural behavioral spare capacity enhancement of the structure by the application of the convergence cross-section is still limited by the expandability due to the limiting state of each material. In order to overcome these limitations, this study reasonably analyzed the construction stages before and after the convergence cross-section constructed and developed a technique for forming multi-point boundary conditions using struts, which are compression members. Based on the existing cases, a reasonable construction step for forming the material composite section of the entire structural system of the structure was derived, and a numerical analysis model for a specific part was constructed to analyze the behavior of the strut application. As a result of this study, the effect of reducing the sectional force of 7.40% in beam-column joint and 6.31% in the center of girder was derived, and the deflection, which is a measure of the serviceability of the structure, improved by 54.41% from the installation and dismantling of strut members at each construction stage.

• Wind and Structures
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• 제23권1호
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• pp.45-57
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• 2016

Open-cross-section composite beam (OCB) tends to suffer vortex-induced vibration (VIV) due to its bluff aerodynamic shape. A cable-stayed bridge equipped with typical OCB is taken as an example in this paper to conduct sectional model wind tunnel test. Vortex-induced vibration is observed and maximum vibration amplitudes are obtained. CFD approach is employed to calculate the flow field around original cross sections in service stage and construction stage, as well as sections added with three different countermeasures: splitters, slabs and wind fairings. Results show that flow separate on the upstream edge and cause vortex shedding on original section. Splitters can only smooth the flow field on the upper surface, while slabs cannot smooth flow field on the upper or lower surface too much. Thus, splitters or slabs cannot serve as valid aerodynamic means. Wind tunnel test results show that VIV can only be mitigated when wind fairings are mounted, by which the flow field above and below the bridge deck are accelerated simultaneously.

• 패션비즈니스
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• 제21권1호
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• pp.74-87
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• 2017

The aim of this study was to analyze the features of bodice patterns modeled using a dress form that represents Korean female fashion models' body features. A controlled experiment was carried out using an existing dress form that has been frequently used in South Korea. The purpose of the study was to suggest notable findings derived from understanding the development of bodice patterns for Korean female fashion models. The comparison of features of bodice patterns from the developed and existing dress forms was carried out with consideration of the upper body features of the developed dress form, such as body angles and body cross-sectional shapes. The following results were derived from the investigations. (1) The angles of the upper and lower breast cups of the developed dress form differed to those of the existing dress form, showing a 5.0cm smaller front shoulder dart and a 3.5 larger ㎝ ㎝ front waist dart within the bodice patterns. (2) The body angle features of the developed dress form included a straighter neck and shoulder blade and more concave center back than the existing dress form, with a 2.0 reduced back neck height and a 4.8 larger back waist dart for ㎝ ㎝ the bodice back panel. The more realistic body angles of the developed dress form anticipate the improvement of garment pattern-making. (3) The altered shoulder angles resulted in an increased size of the back shoulder dart and a decreased size of the front shoulder height within the bodice patterns. (4) The increased rate of curvature of cross-sectional shapes on the bust and waist circumferences of the developed dress form resulted in an increase in the sizes of the front and back waist darts.

• Asian Pacific Journal of Cancer Prevention
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• 제13권1호
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• pp.295-300
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• 2012

Breast self-examination (BSE) is important for early diagnosis of breast cancer (BC). However, the majority of Turkish women do not perform regular BSE. We aimed to evaluate the effects of education level on the attitudes and behaviors of women towards BSE. A descriptive cross-sectional study was conducted on 413 women (20-59 years), divided into university graduates (Group I, n = 224) and high school or lower graduates (Group II, n = 189). They completed a 22-item scale assessing the knowledge level, attitudes and behaviors regarding BSE, and the Turkish version of the Champion's Revised Health Belief Model. A significantly higher number of women in Group II did not believe in early diagnosis of BC. A significantly higher number of Group I had conducted BSE at least once, and their BSE frequency was also significantly high. Moreover, a significantly lower number of Group I women considered themselves to not be at risk for BC and the scores for "perceived susceptibility" and "perceived barriers" were significantly higher. Logistic regression analysis identified the university graduate group to have a higher likelihood of performing BSE, by 1.8 times. Higher educational levels were positively associated with BSE performance. Overall, the results suggest that Turkish women, regardless of their education level, need better education on BSE. Consideration of the education level in women will help clinicians develop more effective educational programs, resulting in more regular practice and better use of BSE.

• 구강회복응용과학지
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• 제35권2호
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• pp.55-63
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• 2019

본 논문은 기존에 선행되었던 연구들을 바탕으로 디지털 모형의 정확도를 평가하는 여러 가지 방법에 관하여 정리하였다. 디지털 모형의 정확도 평가 시, 시험자 교육과 인공적 지표의 사용을 통해 오차를 줄일 수 있다. 디지털 치아 모형의 정확도 평가법은 크게 선형 측정법, 2차원 단면 분석법, 3차원 최적합 분석법으로 분류할 수 있다. 스캐너의 기술이 발전함에 따라 디지털 인상 기술과 전통적 인상법의 정확도를 비교하는 많은 연구들이 이루어지고 있다. 다양한 방법을 이용하여 디지털 모형의 정확도를 평가할 수 있으며, 앞으로 스캐너의 기술 향상 및 3차원 모형 분석 소프트웨어의 개발에 따라 디지털 모형의 정확도 평가 방법이 더욱 효과적으로 변화할 것이라 생각된다. 이 논문에서는 디지털 모형의 정확도를 평가하는 방법들에 대해 소개하고, 각각의 상황에 따른 효과적인 정확도 분석법에 대해 알아보고자 한다.

• Safety and Health at Work
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• 제13권2호
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• pp.240-247
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• 2022

Background: Although insomnia and constipation are highly prevalent worldwide, studies examining a possible association between them are lacking. We examined the relationship between insomnia and constipation in shift workers who have a high prevalence of insomnia and other diseases. Methods: This study had a multicenter cross-sectional design and conducted using health examination data including self-reported questionnaires. In total, 12,879 and 4,650 shift workers were enrolled in Severance Hospital and Wonju Severance Hospital, respectively, during 2015-2017. Multivariate logistic regression models and subgroup analysis were performed in each center with the same protocol, using a common data model. Results: The mean age of the total population was 44.35 (standard deviation = 8.75); the proportion of males was 56.9%. Female sex, being underweight and non-smoker were strongly associated with an increased risk of constipation symptom (p < 0.001). Pooled odds ratios (ORs) were calculated using ORs of both centers with weights; there was a significant dose-response relationship (sub-threshold 1.76 [95% confidence interval [CI] 1.62-1.91]; moderate 2.28 [95% CI 2.01-2.60]; severe 4.15 [95% CI 3.18-5.41] in the final model, p for trend < 0.001). Subgroup analysis performed by stratifying sex and pooled ORs showed a similar trend to that of the entire group. Conclusion: We observed a strong correlation between insomnia and constipation in this population. Our findings may help in formulating guidelines and policies to improve quality of life in shift workers through the management of sleep quality and proper bowel function. This study is the first to report this relationship among people working in shifts.

• Journal of Preventive Medicine and Public Health
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• 제55권3호
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• pp.297-306
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• 2022

Objectives: The incidence of cardiovascular disease (CVD) mortality is increasing in developing countries. This study aimed to decompose the socioeconomic inequality of CVD in Iran. Methods: This cross-sectional population-based study was conducted on 20 519 adults who enrolled in the Ardabil Non-Communicable Disease cohort study. Principal component analysis and multivariable logistic regression were used, respectively, to estimate socioeconomic status and to describe the relationships between CVD prevalence and the explanatory variables. The relative concentration index, concentration curve, and Blinder-Oaxaca decomposition model were used to measure and decompose the socioeconomic inequality. Results: The overall age-adjusted prevalence of CVD was 8.4% in northwest Iran. Multivariable logistic regression showed that older adults, overweight or obese adults, and people with hypertension and diabetes were more likely to have CVD. Moreover, people with low economic status were 38% more likely to have CVD than people with high economic status. The prevalence of CVD was mainly concentrated among the poor (concentration index, -0.077: 95% confidence interval, -0.103 to -0.060), and 78.66% of the gap between the poorest and richest groups was attributed to differences in the distribution of the explanatory variables included in the model. Conclusions: The most important factors affecting inequality in CVD were old age, chronic illness (hypertension and diabetes), marital status, and socioeconomic status. This study documented stark inequality in the prevalence of CVD, wherein the poor were more affected than the rich. Therefore, it is necessary to implement policies to monitor, screen, and control CVD in poor people living in northwest Iran.

• 대한기계학회논문집B
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• 제27권12호
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• pp.1744-1749
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• 2003

The purpose of this study is to obtain the information about the development process of GDI spray. To acquire the characteristics of GDI spray, the computational study of hollow cone spray for high-pressure swirl injectors was performed. Several hybrid models using the modified KIVA code have been introduced and compared. WB model and LISA model were used for the primary breakup, and DDB and APTAB models were used for secondary breakup. To compare with the calculated results, the experimental results such as cross-sectional images and SMD distribution were acquired by laser Mie scattering technique and Phase Doppler Analyzer respectively. The results show that LISA+APTAB hybrid model has the best prediction for spray formation process.

• 농업과학연구
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• 제37권3호
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• pp.509-514
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• 2010

The purpose of this study is to analyze the technical efficiency and its determinants for Korean Apiculture farming by using from door to door and e-mail inquiry data. The analysis was implemented through the Cobb-Douglas stochastic frontier production function (SFPF) model including the technical inefficiency effect model for cross-sectional data. To measure the SFPF model, honey production was used for a dependent variable, and for input variables labor cost, preventive cost, material cost, feeding cost, depreciation cost were used. Farmer's age, farmer's career, farming scale, full-time or half-time firm and movement or fixed firm variables were used to measure the inefficiency effect model. The average technical efficiency on apiculture farming in Korea is estimated to be 0.8112. It means that there were technical inefficiency of about 18.88% in Korea apiculture farming. In this study there are some suggestions which could increase the technical efficiency of Korean apiculture farming.