• Title/Summary/Keyword: reinforcing factor

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Relationships of Self-Efficacy to Creative Disposition and Ability in University Students Major in Health Care (간호.보건계 대학생의 자기효능감과 창의적 성향 및 능력간의 관계)

  • Gang, So-Yeong
    • Korea Journal of Hospital Management
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    • v.14 no.3
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    • pp.49-66
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    • 2009
  • Purpose : This study was aimed at examining the relationships of university students' self-efficacy to creative disposition and creative thinking ability. Method : A descriptive study was conducted with a sample of 320 students enrolled 4-year-undergraduate academic programs major in nursing as well as elderly care management in one University located in Pusan, Korea. This study used: (a) 24 items of Self-Efficacy Scale originally developed by Kim & Cha(1996), and (b) 39 items of creative thinking ability and 16 items of creative attitudes in a Self-Report Form of Integrative Creativity Scale developed by Bak & Kang(2006). The data were analyzed by using Pearson correlation and hierarchical multiple regression methods. Result : University students' self-efficacy has significantly positive impact on creative thinking ability(p<.001) with 26.4% of the variance and creative disposition(p<.001) with 48.9%. Creative thinking ability as well as the disposition related to creativity that university students possessed were significantly influenced by efficacy on self-control and efficacy on taking difficult tasks. Conclusion : This result supports Social Cognitive Theory and Investment Theory of Creativity in terms that self-efficacy is the factor affecting fostering creative ability and demonstration of creativity potential to the real. This also implies that healthcare educational programs reinforcing students' self-efficacy would contribute to breed them to healthcare professionals with creative competency.

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Tensile Behavior and Fracture Properties of Ductile Hybrid FRP Reinforcing Bar for Concrete Reinforcement (콘크리트 보강용 고연성 하이브리드 FRP 보강근의 인장 및 파괴 특성)

  • Park, Chan-Gi;Won, Jong-Pil
    • Journal of The Korean Society of Agricultural Engineers
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    • v.46 no.1
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    • pp.41-51
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    • 2004
  • FRP re-bar in concrete structures could be used as a substitute of steel re-bars for that cases in which aggressive environment produce high steel corrosion, or lightweight is an important design factor, or transportation cost increase significantly with the weight of the materials. But FRP fibers have only linearly elastic stress-strain behavior; whereas, steel re-bar has linear elastic behavior up to the yield point followed by large plastic deformation and strain hardening. Thus, the current FRP re-bars are not suitable concrete reinforcement where a large amount of plastic deformation prior to collapse is required. The main objectives of this study in to evaluate the tensile behavior and the fracture mode of hybrid FRP re-bar. Fracture mode of hybrid FRP re-bar is unique. The only feature common to the failure of the hybrid FRP re-bars and the composite is the random fiber fracture and multilevel fracture of sleeve fibers, and the resin laceration behavior in both the sleeve and the core areas. Also, the result of the tensile and interlaminar shear stress test results of hybrid FRP re-bar can provide its excellent tensile strength-strain and interlaminar stress-strain behavior.

Factors Affecting the Usage of an ERP System in Operation : A Socio-technical View with User Orientation (운영 중인 ERP 시스템의 활용도에 영향을 미치는 요인에 관한 연구 : 사용자 중심의 통합된 사회-기술적 관점에서)

  • Cho, Eun-Kyong;Min, Dai-Hwan
    • Journal of Information Technology Services
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    • v.9 no.2
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    • pp.129-149
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    • 2010
  • Although many organizations have implemented and used ERP systems for years, industry reports point out that the usage level does not reach their expectation. As a result, they do not enjoy the benefits from the investment into ERP systems. This study attempts to develop a research model and test the model empirically for identifying factors that affect the usage of an ERP system at a public organization. This study has classified potential factors into three groups of technical system characteristics (usability, usefulness), organizational support characteristics (operational support, education and training, evaluation and measurement), and user characteristics (organizational citizenship, self-efficacy). Then, a structural equation model has been established on the basis of previous literature and tested with empirical data. In summary, this study has found that self-efficacy, usefulness, and operational support have an effect on the ERP usage. Self-efficacy is the strongest factor; Usefulness is the second; and the third is operational support. On the contrary to the previous literature, this study has not found a significant effect of organizational citizenship on the usage. The result confirms that an organization can increase the ERP usage by improving the usefulness of an ERP system to some extent. However, to boost the usage further, the result implies that organizations need to strengthen the self-efficacy of their members by reinforcing operational support, providing education and training steadily, and establishing an evaluation mechanism in relation with the ERP usage.

Synthesis of Graphene Coated Aluminum Powders by Self-assemble Reaction (자기 조립 반응에 의한 그래핀이 코팅된 알루미늄 입자의 합성 방법)

  • Hwang, Jin Uk;Tak, Woo Seong;Nam, Sang Yong;Kim, Woo Sik
    • Journal of Powder Materials
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    • v.26 no.5
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    • pp.383-388
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    • 2019
  • To improve the mechanical properties of aluminum, graphene has been used as a reinforcing material, yielding graphene-reinforced aluminum matrix composites (GRAMCs). Dispersion of graphene materials is an important factor that affects the properties of GRAMCs, which are mainly manufactured by mechanical mixing methods such as ball milling. However, the use of only mechanical mixing process is limited to achieve homogeneous dispersion of graphene. To overcome this problem, in this study, we have prepared composite materials by coating aluminum particles with graphene by a self-assembly reaction using poly vinylalcohol and ethylene diamine as coupling agents. The scanning electron microscopy and Fourier-transform infrared spectroscopy results confirm the coating of graphene on the Al surface. Bulk density of the sintered composites by spark plasma sintering achieved a relative density of over 99% up to 0.5 wt.% graphene oxide content.

Influence of steel fiber and reinforcing details on the ultimate bearing strength of the post-tensioning anchorage zone

  • Kim, Jin-Kook;Yang, Jun-Mo;Kwon, Yangsu
    • Structural Engineering and Mechanics
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    • v.59 no.5
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    • pp.867-883
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    • 2016
  • In this paper, the effects of steel-fiber and rebar reinforcements on the ultimate bearing strength of the local anchorage zone were investigated based on experiments and comparisons between test results and design-equation predictions (AASHTO 2012, NCHRP 1994). Eighteen specimens were fabricated using the same anchorage device, which is one of the conventional anchorage devices, and two transverse ribs were used to secure an additional bearing area for a compact anchorage-zone design. Eight of the specimens were reinforced with only steel fiber and are of two concrete strengths, while six were reinforced with only rebars for two concrete strengths. The other four specimens were reinforced with both rebars and steel fiber for one concrete strength. The test and the comparisons between the design-equation predictions and the test results showed that the ultimate bearing strength and the section efficiency are highly affected by the reinforcement details and the concrete strength; moreover, the NCHRP equation can be conservatively applied to various local anchorage zones for the prediction of the ultimate bearing strength, whereby conditions such as the consideration of the rib area and the calibration factor are changed.

Effect analysis of ISLOCA pathways on fission product release at Westinghouse 2-loop PWR using MELCOR

  • Kim, Seungwoo;Park, Yerim;Jin, Youngho;Kim, Dong Ha;Jae, Moosung
    • Nuclear Engineering and Technology
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    • v.53 no.9
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    • pp.2878-2887
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    • 2021
  • As the amount of fission product released from ISLOCA was overestimated because of conservative assumptions in the past, several studies have been recently conducted to evaluate the actual release amount. Among several pathways for the ISLOCA, most studies were focused on the pathway with the highest possibility. However, different ISLOCA pathways may have different fission product release characteristics. In this study, fission product behavior was analyzed for various pathways at the Westinghouse two-loop plant using MELCOR. Four pathways are considered: the pipes from a cold leg, from a downcomer, from a hot leg to the outlet of RHR heat exchanger, and the pipe from the hot leg to the inlet of RHR pump (Pathway 1-4). According to the analysis results, cladding fails at around 2.5 h in Pathways 1 and 2, and on the other hand, about 3.3 h in Pathways 3 and 4 because the ISLOCA pathways affect the safety injection flow path. While the release amount of cesium and iodine ranges between 20 and 26% in Pathways 1 to 3, Pathway 4 allows only 5% to the environment because the break location is submerged. Also, as more than 90% of cesium released to the environment passes through the personnel door, reinforcing the pressure capacity of the doors would be a significant factor in the accident management of the ISLOCA.

Effect of Cork Extract on the Mechanical Property of Thermoplastic Polyurethane

  • Taehoon Oh;Seung-Hyun Cho;Bumyong Yoon;Hyejung Yoon;Jonghwan Suhr
    • Composites Research
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    • v.36 no.2
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    • pp.86-91
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    • 2023
  • Thermoplastic polyurethane (TPU) is a material whose mechanical properties change according to the phase separation of its unique internal microstructure and is therefore used in various industries. Use of TPU as composites helps in improving the desirable characteristics and properties in accordance with usage. Eco-friendly fillers one of the fillers are on the rise and those are mostly used for reinforcing role. Suberin, which can be extracted from cork, is the main component of cork. It is known to serve high damping property of elastomer composite. The original chemical structure of Suberin is an aliphatic polyester aggregate. In this research, Suberin is obtained after depolymerization into an oligomer having 2 or 3 ester bonds through alkaline hydrolysis. The extracted suberin was added to the matrix which is thermoplastic polyurethane as an eco-friendly filler for improving vibration damping property. As a result, when 10 wt% of suberin was added into thermoplastic polyurethane the existing trade-off relationship was overcome. And it is attained the elastic modulus and damping factor at room temperature improving 92 and 59%, respectively, compared to the original matrix. Those results are from the interaction between the microstructure of TPU and suberin.

Flexural Overstrength of Reinforced Concrete Bridge Columns for Capacity Design (철근콘크리트 교각의 성능보장설계를 위한 휨 초과강도)

  • Lee, Jae-Hoon;Ko, Seong-Hyun;Choi, Jin-Ho
    • Journal of the Earthquake Engineering Society of Korea
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    • v.10 no.5 s.51
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    • pp.85-97
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    • 2006
  • Capacity design is to guarantee ductile failure of whole bridge system by preventing brittle failure of columns and any other structural elements until the columns develope fully enough plastic deformation capacity. This concept has been explicitly regulated in most bridge design specifications of foreign countries except the current Korea Bridge Design Specifications. In the capacity design, the transformed shear force from flexural overstrength of reinforced concrete column is used as the design lateral shear force for shear design of columns and design of footings and piles. Different calculating methods are adopted by the design specifications, since the variability of material strength and construction circumstances of the local regions should be considered. This paper proposed material overstrength factors by investigating 3,407 reinforcing bar data and 5,405 concrete compressive strength data collected in Korean construction sites. It also proposed calculating procedures for flexural overstrength of reinforced concrete columns using the material overstrength. Finally, overstrength factor was proposed as 1.5 by investigating 1,500 column section data from moment-curvature analysis using the material overstrength.

Stability Analysis of Geocell Reinforced Slope During Rainfall (강우 시 지오셀 보강 사면의 안정성 평가에 관한 연구)

  • Shin, Eun-Chul;Kim, Jang-Ill
    • Journal of the Korean Geosynthetics Society
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    • v.16 no.4
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    • pp.33-41
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    • 2017
  • In this study, the increment effect of safety factor according to increasing of horizontal permeability coefficient is analyzed when geocell is installed on the slope for protection. To evaluate the horizontal permeability and reinforcement effect, the laboratory tests such horizontal permeability test were conducted. According to the laboratory test results, as the porosity rate of geocell increases, the coefficient of horizontal permeability is also increased. And also, regardless of the different types of filled materials, the coefficient of horizontal permeability is improved in a geocell reinforced ground compare with the non-reinforced ground. Laboratory test results and the rainfall intensity were applied to the numerical modeling of slope for seepage analysis and stability analysis of slope by using Soilworks, numerical analysis program. As a result of the slope stability analysis, it is confirmed that the installed geocell on the slope facilitates the drainage of water on the surface of slope. Hence, the ground water elevation is suppressed. Therefore, the safety factor of the slope is increased by the increasing of the internal friction angle, apparent cohesion, and coefficient of horizontal permeability by reinforcing the slope with geocell.

Evaluation on Effective Width of Concrete Unfilled Composite Steel Grid Deck (콘크리트 비충전 강합성 바닥판의 유효폭 평가)

  • Park, Young Hoon;Lee, Seung Yong
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.37 no.3
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    • pp.521-529
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    • 2017
  • In this study, analyzed the effective width of concrete unfilled composite steel grid deck which has different shear connector details from that of composite bridge. The effective width of concrete unfilled composite steel grid deck according to effective width calculation method, load size and main bearing bar spacing-span ratio was evaluated. As a result of analysis, it is analyzed that the effective width is calculated to be nearly equal to the actual effective width by idealizing the stress shape as a trapezoidal shape. In addition, shear hole penetration reinforcing bars applied to increase the shear strength is shown to increase the effective width. From the results of the analysis of the effective width according to main bearing bar spacing-span ratio, proposes the correction factor that can calculate the effective width ratio of the unfilled steel composite steel grid deck.