• Advanced Composite Materials
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• 제18권1호
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• pp.77-93
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• 2009

This paper investigated the damage transition mechanism between the fiber-breaking mode and the fiber-avoiding crack mode when the fiber-length is reduced in the unidirectional discontinuous carbon fiber-reinforced-plastics (CFRP) composites. The critical fiber-length for the transition is a key parameter for the manufacturing of flexible and high-strength CFRP composites with thermoset resin, because below this limit, we cannot take full advantage of the superior strength properties of fibers. For this discussion, we presented a numerical model for the microscopic damage and fracture of unidirectional discontinuous fiber-reinforced plastics. The model addressed the microscopic damage generated in these composites; the matrix crack with continuum damage mechanics model and the fiber breakage with the Weibull model for fiber strengths. With this numerical model, the damage transition behavior was discussed when the fiber length was varied. The comparison revealed that the length of discontinuous fibers in composites influences the formation and growth of the cluster of fiber-end damage, which causes the damage mode transition. Since the composite strength is significantly reduced below the critical fiber-length for the transition to fiber-avoiding crack mode, we should understand the damage mode transition appropriately with the analysis on the cluster growth of fiber-end damage.

• 한국대기환경학회지
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• 제25권1호
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• pp.26-37
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• 2009

Recently rapid environmental changes due to desertification and industrialization in China make a threat to Korea, especially during Asian Dust Event (ADE). This study was aimed to compare symptoms and behaviors related to ADE between Korea and China. We conducted questionnaires on self-reported symptoms and behaviors before and during ADE. Korean and Chinese subjects were grouped into children, adults, and elderly by nation (n=791). Statistical analyses were performed by $X^2$-test, Fisher's exact test, t-test and chow's test for comparing differences between Korean and Chinese. We estimated the odds ratio for perceived symptoms during ADE by preventive behavior, using Generalized Estimation Equation (GEE). The study indicated that there were significant differences between symptoms in Korea and those in China such as cold, cough, and sore throat, especially in elderly. Preventive behaviors such as avoiding outdoor activity and wearing sunglasses were more often performed in China than Korea. However wearing mask was more often performed in Korea than China. After adjusting for age, sex, educational level, and smoking status, the odds ratio (OR) of dry cough symptom in Korea was significantly decreased by closing the windows and wearing a mask during ADE. In China, the OR of dry cough symptom was decreased by wearing a mask and avoiding outdoor activity. We found that China which had higher performance of preventive behavior showed lower prevalence of symptoms during ADE than Korea. Also preventive behaviors could affects prevalence of symptoms during ADE. This results suggest that preventive behavior. could reduce symptoms during ADE and there are needed for. more attentions to reduce a threat of ADE.

• 여성건강간호학회지
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• 제24권2호
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• pp.209-218
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• 2018

Purpose: This study was conducted among older women to (1) identify their levels of knowledge, self-efficacy, and health behavior in dealing with osteoporosis and falls and (2) explore the relationships between the study variables based on a health-beliefs model. Methods: With a cross-sectional survey design, we recruited 94 older women of ages from 65 to 74 at a community setting via convenience sampling. The study participants completed two sets of structured questionnaires (on osteoporosis and fall prevention). Results: The general characteristics of the study participants demonstrated that the women were at high risk for osteoporosis and falls. Overall, the levels of knowledge about osteoporosis and falls, their self-efficacy, and their preventive behaviors were average or slightly above. The relationships between the study variables showed that self-efficacy and healthy behavior, such as doing osteoporosis exercise, eating an osteoporosis diet, and avoiding falls, were related (r=38, p<.001; r=.33, p<.05; r=.26, p<.05). In addition, there were statistically significant relationships between osteoporosis and fall prevention knowledge (r=.37~.46, p<.001), self-efficacy (r=.50~.53, p<.001), and preventive behaviors (r=.50, p<.001). Conclusion: The women's scores on osteoporosis and fall knowledge, self-efficacy, and preventive behaviors suggest an urgent need for the implementation of educational programs for older women. A close relationship between self-efficacy and health behaviors implies a need for transformation of a traditional one-way lecture form.

• Asian Pacific Journal of Cancer Prevention
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• 제14권12호
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• pp.7663-7668
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• 2013

Background: Skin cancer is a global health problem that can be prevented by protective behavior promoted by nurses. In Turkey, only few studies have examined current knowledge of nurses related to skin cancer and to reveal their attitudes towards sun exposure and current protective behavior. Materials and Methods: This descriptive cross-sectional study was performed from March 11 to May 30, 2013 with a study sample of 310 nurses working in two state hospitals located in Karab$\ddot{u}$k and Safranbolu. Results: Mean age of the nurses was $30.3{\pm}6.89$ years and 96.1% of them had graduated with a Bachelor degree. The participants were predominantly female (n=284). Knowledge level about skin cancer was significantly higher for females compared to males. Conclusions: Nurses do not have sufficient knowledge about skin cancer and are not adequately protecting themselves from ultraviolet light, the primary risk factor for skin cancer. While they demonstrated a responsible attitude towards avoiding sunburn and the need for adequate sun protection, they do not fully appreciate the extent to which the sun can cause skin cancer and that they lack full understanding about the need to protect the skin from burning and to avoid long term sun exposure in Turkey.

• Geomechanics and Engineering
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• 제7권1호
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• pp.87-103
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• 2014

This study investigated the effect of soil-structure interaction (SSI) on the response of base-isolated buildings. Seismic isolation can significantly reduce the induced seismic loads on a relatively stiff building by introducing flexibility at its base and avoiding resonance with the predominant frequencies of common earthquakes. To provide a better understanding of the movement behavior of multi-story structures during earthquakes, this study analyzed the dynamic behavior of multi-story structures with high damping rubber bearing (HDRB) behavior base isolation systems that were built on soft soil. Various models were developed, both with and without consideration of SSI. Both the superstructure and soil were modeled linearly, but HDRB was modeled non-linearly. The behavior of the specified models under dynamic loads was analyzed using SAP2000 computer software. Erzincan, Marmara and Duzce Earthquakes were chosen as the ground motions. Following the analysis, the displacements, base shear forces, top story accelerations, base level accelerations, periods and maximum internal forces were compared in isolated and fixed-base structures with and without SSI. The results indicate that soil-structure interaction is an important factor (in terms of earthquakes) to consider in the selection of an appropriate isolator for base-isolated structures on soft soils.

• 한국주조공학회지
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• 제20권6호
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• pp.368-376
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• 2000

Rheology forming technology has been accepted as a new method for fabricating near net shaped products with lightweight aluminum alloys. The rheology forming process consists of reheating process of billet, billet handling, filling into the die cavity and solidification of rheology formed part. The rheology forming experiments are performed with two different die temperatures ($T_d$ = $200^{\circ}C$, $300^{\circ}C$) and orifice gate type. The filling behavior and various defects of Al-Si materials with wear resistance (A357, A390 and ALTHIX 86S) fabricated in rheology forming process are evaluated in terms of alloying elements and surface non-uniformity. Finally, the methods to obtain the rheology formed products with high quality are described by solutions for avoiding the surface and internal defects.

• 자동차안전학회지
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• 제5권1호
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• pp.25-30
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• 2013

The main purpose of this research is to predict dynamic behavior of door locking system for side impact safety and the design process to avoid door opening is introduced. The equations of motion that represent the system are obtained from the energy equation. From them, the motion of door handle is predicted by using Runge-Kutta $4^{th}$ order method and the simulation result is compared with the real crash data. Also, the design guide to define the properties of door locking system from the standpoint of avoiding door opening phenomenon is introduced.

• 한국식생활문화학회지
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• 제29권4호
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• pp.336-341
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• 2014

This study examined relationships among healthy food awareness, behavioral intention toward healthy foods, and actual behavior of Generation Y consumers. This study hypothesized that Generation Y consumers are aware of healthy foods and more likely to eat healthy foods while avoiding junk foods. According to structural equation modeling, all hypothesized paths were statistically significant, meaning that the three constructs in the model showed positive relationships with each other. Results showed that this group of college students is generally aware of healthy foods and have positive intentions toward healthy food choices. Therefore, university foodservice management needs to continue to improve their menus in order to attract this new generation of college student consumers.

• Coupled systems mechanics
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• 제11권6호
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• pp.525-542
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• 2022

In this work we present an advanced approach to the design of small wind turbine support steel structures. To this end we use an improved version of previously developed geometrically exact beam models. Namely, three different geometrically exact beam models are used, the first two are the Reissner and the Kirchhoff beam models implementing bi-linear hardening response and the third is the Reissner beam capable of also representing connections response. All models were validated in our previous research for a static response, and in this work they are extended to dynamic response. With these advanced models, we can perform analysis of four practical solutions for the installation of small wind turbines in new or existing buildings including effects of elastoplastic response to vibration problems. The numerical simulations confirm the robustness of numerical models in analyzing vibration problems and the crucial effects of elastoplastic response in avoiding resonance phenomena.

• Asian Pacific Journal of Cancer Prevention
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• 제14권1호
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• pp.103-109
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• 2013

Background: The objective of this study is to determine knowledge about lung cancer among secondary school male teachers in Kudat, Sabah, Malaysia. Materials and Methods: A cross-sectional study was conducted among three secondary schools located in Kudat district, Sabah, Malaysia during the period from June until September 2012. The protocol of this study was approved by ethics committee of Management and Science University, Malaysia. The aims were explained and a consent form was signed by each participant. Respondents were chosen randomly from each school with the help of the headmasters. Self-administrated questionnaires, covering socio-demographic characteristics and general knowledge of lung cancer, were distributed. Once all 150 respondents completed the questionnaire, they passed it to their head master for collecting and recording. All the data were analyzed using Statistical Package for the Social Sciences (SPSS) version 13. ANOVA and t-test were applied for univariate analysis; and multiple linear regression for multivariate analysis. Results: A total of 150 male secondary school teachers participated in this study. Their mean age was $35.6{\pm}6.5$ (SD); maximum 50 and minimum 23 years old. More than half of the participants were Malay and married (52%, 79%; respectively). Regarding the knowledge about lung cancer, 57.3% of the participants mentioned that only males are affected by lung cancer. Some 70.7% mentioned that lung cancer can be transmitted from one person to another. More than half (56.7%) reported that lung cancer is not the leading cause of death in Malaysian males. As for risk factors, the majority reported that family history of lung cancer is not involved. However, 91.3% were aware that cigarettes are the main risk factor of lung cancer and more than half (52%) believed that second-hand smoking is one of the risk factor of lung cancer. More than half (51.3%) were not aware that asbestos, ionizing radiation and other cancer causing substances are risk factors for lung cancer. Quitting smoking, avoiding second-hand smoking and avoiding unnecessary x-ray image of the chest (53.3%, 96.0%, 87.3%; respectively) are the main preventive measures mentioned by the participants. For the factors that influence the participants knowledge, univariate and multivariate analysis showed that only race was significant. Conclusions: Overall, the knowledge of school male teachers about lung cancer was low. However, few items were scored high: cigarettes are the main risk factor; avoiding second-hand smoking; and avoiding x-rays. Interventions to increase lung cancer awareness are needed to improve early detection behavior. Increase the price of pack of cigarettes to RM 20 and banning smoking in public places such as restaurants are highly recommended as primary preventive measures.