• 수산해양교육연구
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• 제26권3호
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• pp.611-626
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• 2014

Based on adolescents' perspectives, this study attempts to explore the distinguishing characteristics of teachers that influence students to positively change in areas such as psychological adaptation and development of their potential. Essays focusing on memories of twenty seven significant teachers written by eighteen adolescents in middle schools and high schools in Daegu, Korea in 2011 were used for analyzing the factors that have influenced them to positively change. Subsequently, five critical factors were identified: warmness and acceptance; encouragement and support; communication and understanding; respect and care; modeling and expectation. The adolescents perceived that those factors not only contributed to their psychological wellbeing but also enabled them to positively change and achieve more in life. Moreover, the educational implications focusing on teachers' productive function and healing power were discussed. The role of teachers in reinforcing and building the character students in order to facilitate their holistic development was dealt with. Finally, the reference for promotion of further studies of the research field was made.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1990년도 봄 학술발표회 논문집
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• pp.90-95
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• 1990

It is widely recognized that the strengths of reinforced concrete members have random characteristics due to the variability of the mechanical properties of concrete and steel, the dimensional error as well as incorrect placement of reinforcing bars. Statistical models of the variabilities of strengths of reinforced concrete members, therefore, need to be developed to evaluate the safety level implied in current practices. Based on the probabilistic models of basic factors affecting the R.C. member strengths, in this study, the probabilistic characteristics of member resistance have been studied through Monte Carlo simulation.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1991년도 가을 학술발표회 논문집
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• pp.45-50
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• 1991

This research has been carried out experimently to verify the structural efficiency of the reinforced concrete columns subjected to cyclic lateral loadings in the inelastic range. Sixteen specimens have been used in the tests, the factors such as reinforcing bars, shear-span ratio, axial load level and loading history being taken differently. The load-carrying capacities and the stiffness degradation in the inelastic range by cycle lateral load application have been counted by observing the load-deformation relationship, the crack initiation and propagation and the energy dissipation phenomena.

• Biomolecules & Therapeutics
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• 제22권5호
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• pp.460-466
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• 2014

Nicotine addiction is a worldwide problem. However, previous studies characterizing the rewarding and reinforcing effects of nicotine in animal models have reported inconsistent findings. It was observed that the addictive effects are variable on different factors (e.g. route, dose, and age). Here, we evaluated the rewarding and reinforcing effects of nicotine in different routes of administration, across a wide dose range, and in different age groups. Two of the most widely used animal models of drug addiction were employed: the conditioned place preference (CPP) and self-administration (SA) tests. Nicotine CPP was evaluated in different routes [intraperitoneal (i.p.) and subcutaneous (s.c.)], doses (0.05 to 1.0 mg/kg) and age [adolescent and adult rats]. Similarly, intravenous nicotine SA was assessed in different doses (0.01 to 0.06 mg/kg/infusion) and age (adolescent and adult rats). In the CPP test, s.c. nicotine produced greater response than i.p. The 0.2 mg/kg dose produced highest CPP response in adolescent, while 0.6 mg/kg in adult rats; which were also confirmed in 7 days pretreated rats. In the SA test, adolescent rats readily self-administer 0.03 mg/kg/infusion of nicotine. Doses that produced nicotine CPP and SA induced blood nicotine levels that corresponded well with human smokers. In conclusion, we have demonstrated that nicotine produces reliable CPP [0.2 mg/kg dose (s.c.)] in adolescents and [0.6 mg/kg dose (s.c.)] in adults, and SA [0.03 mg/kg/infusion] in adolescent rats. Both tests indicate that adolescent rats are more sensitive to the rewarding and reinforcing effects of nicotine.

• 한국지반공학회논문집
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• 제27권12호
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• pp.39-52
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• 2011

본 연구에서는 유한요소해석 및 전단강도 감소기법을 적용하여 가압식 그라우팅 쏘일네일로 보강된 사면의 시공 단계를 고려한 사면안정 해석을 수행하였으며 무보강 자연사면 및 중력식 그라우팅 쏘일네일로 보강된 사면의 안전율과 비교함으로써 가압식 그라우팅 쏘일네일의 사면 보강효과를 분석하였다. 그 결과, 가압식 그라우팅 쏘일네일로 보강된 사면의 안전율이 중력식 그라우팅 쏘일네일로 보강된 사면에 비해 50% 이상 크게 나타났으며, 쏘일네일의 길이가 증가할수록 가압에 따른 보강효과가 우수한 것으로 나타났다. 또한 가압에 의해 사면 활동파괴영역이 확대됨에 따라 사면 전단저항 능력이 증가하는 것을 확인하였으며, 쏘일네일의 인발저항력이 사면보강에 가장 큰 영형을 미치는 것을 알 수 있었다.

• Structural Monitoring and Maintenance
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• 제10권4호
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• pp.315-337
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• 2023

During the design phase, it is crucial to determine the interface stresses between the reinforcing plate and the concrete base in order to predict plate end separation failures. In this work, a simple theoretical study of interface shear stresses in beams reinforced with P-FGM and E-FGM plates subjected to an arbitrarily positioned point load, or two symmetrical point loads, was presented using the linear elastic theory. The presence of pores in the reinforcing plate distributed in several forms was also taken into account. For this purpose, we analyze the effects of porosity and its distribution shape on the interracial normal and shear stresses of an FGM beam reinforced with an FRP plate under different types of load. Comparisons of the proposed model with existing analytical solutions in the literature confirm the feasibility and accuracy of this new approach. The influence of different parameters on the interfacial behavior of reinforced concrete beams reinforced with functionally graded porous plates is further examined in this parametric study using the proposed model. From the results obtained in this study, we can say that interface stress is significantly affected by several factors, including the pores present in the reinforcing plate and their distribution shape. Additionally, we can conclude from this study that reinforcement systems with composite plates are very effective in improving the flexural response of reinforced RC beams.

• International Journal of Concrete Structures and Materials
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• 제18권1E호
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• pp.29-34
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• 2006

Elastic modulus, tensile and bond capacities are important factors for developing an effective reinforcing action of a flexural member as a reinforcing material for concrete structures. Reinforcement must have enough bond capacity to prevent the relative slip between concrete and reinforcement. This paper presents an experimental study to clarify the bond capacity of prestressed carbon fiber reinforced polymer(CFRP) rod manufactured by an automatic assembly robot. The bond characteristics of CFRP rods with different pitch of helical wrapping were analyzed experimentally. As the result, all types of CFRP rods show a high initial stiffness and good ductility. The mechanical properties of helical wrapping of the CFRP rods have an important effect on the bond of these rods to concrete after the bond stress reached the yield point. The stress-slip relationship analyzed from the pull-out test of embedded cables within concrete was linear up to maximum bond capacity. The deformation within the range of maximum force seems very low and was reached after approximately 1 mm. The average bond capacity of CF20, CF30 and CF40 was about 12.06 MPa, 12.68 MPa and 12.30 MPa, respectively. It was found that helical wrapping was sufficient to yield bond strengths comparable to that of steel bars.

• 한국직업건강간호학회지
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• 제29권3호
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• pp.208-218
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• 2020

Purpose: Nurses' job satisfaction corresponds with personal intrinsic value, and is the strongest predicting turnover and job retention intention. This study identified the effectiveness of job satisfaction interventions related to reinforcing intrinsic motivation (JSI-RIM) for hospital nurses. Methods: This study used four core non-Korean databases (Cochrane Library, CHINHL, EMBASE, PubMed), and five Korean databases to search for RCT and NRCT articles published in English and Korean from inception to June 2019. Meta-analysis was performed using the RevMan 5.3.5 program. Results: Thirteen studies featuring 645 hospital nurses were selected for final analysis. A significant large effect was noted on self-efficacy. The effect size on perceived stress and job satisfaction were moderate; however, the effect on resilience outcomes was not significant. Conclusion: This study generated scientific evidence that would facilitate efficient job adaptation for nurses. Additionally, intrinsic factors, including job identity and meaning of work, need to be included in JSI-RIM.

• 한국건축시공학회지
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• 제10권4호
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• pp.123-132
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• 2010

Rebar work accounts for approximately 30% of the total construction costs for rebars and concrete. Recently, the high rising prices of rebars have become one of the principle factors of rising construction costs. Therefore, construction companies are putting much effort into loss reduction of rebars. Consequently, in this study, we wished to present loss reduction methods of rebars before the preparation of the placing drawings. To devise such methods, we collected previous case studies and analyzed methods that were applied for loss reduction. As a result of the analysis, we were able to find the following methods for loss reduction of rebars: method of reducing the number of splices at the mat foundation, method of reducing splice length at the internal columns or walls of the underground parking lot, method of reducing cap-ties of internal beams of basement floors excluding perimeter beams, and method of reducing anchorage length at the internal column or wall of the underground parking lot. Based on those analysis results, we presented our own loss reduction methods of rebars. Applying our methods resulted in considerable loss reduction.

• 한국방재학회 논문집
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• 제7권4호
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• pp.13-18
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• 2007

본 연구에서는 구조물의 내구성 설계 시에 영향을 미치는 설계인자들에 대한 고찰을 하고, 내구성 설계에 사용되고 있는 기준에 대한 국내외 문헌연구를 수행하였으며, 국내기준을 가지고 지하 구조물 단면을 대상으로 내구성 설계를 수행하였다. 국내 지하구조물의 내구설계 지침에 따른 결과는 사용 철근의 직경을 작게 하고 간격을 좁힐수록 구조물의 내구성에 유리한 것으로 나타났으며, 환경지수 제한치를 상회하는 내구지수를 가지기 위해서는 최소한 6.6cm의 피복을 가져야 하며, 내구지수와 내구지수 증분치 변화의 최대 철근피복은 12cm인 것으로 나타났다. 별도의 제한규정이 없는 경우, 철근피복의 최소치와 최대치 사이에서 중성화로 인한 내구연한은 철근피복에 비례하였다.