• 한국안전학회지
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• 제35권2호
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• pp.61-66
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• 2020

As asbestos-containing buildings are getting older, asbestos deconstruction works are increasing. As a result, accident risks such as falls, cuts, electric shocks, and suffocation are increasing. Existing studies are mostly about health management and institutional policy research and there is little research on work risk. So workplace risk assessments that are easily applicable in the field are required to be applied. Sealing is the first process of asbestos deconstruction and is the first step to ensure worker's safety. Job Safety Analysis(JSA) and Checklist were used to identify the risk factors and to calculate the level of the risk. By comparing the two risk assessment tools, it was figured out that the JSA is appropriate for the initial process and change of work procedure while Checklist is appropriate for repetitive work. Because the sealing process is sort and simple, it is unlikely to cause serious injury. But since the risk of falling and cuts are exist, safety education and supervision are necessary to maintain a safe working environment.

• Advances in concrete construction
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• 제10권4호
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• pp.279-287
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• 2020

The practice of splicing reinforcing bars in reinforced concrete structures to manage insufficient bar length is a common approach, which is mainly due to transportation limitations on bar length. The splicing of reinforcing bars side by side offers a simple and economical solution to the problem of continuity. This paper examines the influence of different structural parameters such as concrete cover, lap splice length, shear links confinement and concrete strength on the lap splices based on an extensive experimental database of laps and anchorage. The current study shows that increasing the lap splices beyond 50Ø has no additional benefit for increasing its strength. The results also show that relative to the measured stress, specimens with larger concrete side covers shows higher splice stress compared to the samples with smaller concrete covers.

• Asian-Australasian Journal of Animal Sciences
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• 제30권4호
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• pp.449-454
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• 2017

Recently, increasing attention has been paid to the welfare of farm animals, which have been evaluated using behavioral and physiological measures. However, so far, the measures have almost always been used to estimate poor welfare. In this review, firstly we focus on how oxytocin (OT) relates to positive social behavior, pleasure, and stress tolerance, and second on which management factors stimulate OT release. OT induces maternal and affiliative behaviors and has an anti-stress effect. Further, OT is produced during enjoyable events, and has positive feedback on its own release as well. Therefore, to some extent, the relationship of OT to positive normal behavior was mutually beneficial-heightened OT concentration owing to comfortable rearing conditions induces positive social behavior, which in turn may increase OT concentration. Hence, studies on animal welfare should pay more attention to increasing comfort and the stress tolerance, rather than only focusing on when stress occurs in farm animals.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2004년도 제28회 KOSCO SYMPOSIUM 논문집
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• pp.118-123
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• 2004

The combustion characteristics of 0.03MW turbulent methane/oxygen diffusion flames have been investigated to give basic informations for designing industrial oxyfuel combustors. NOx reduction has become one of the most determining factors in the combustor design since 3-5% nitrogen is intrinsically included from the current oxygen producing processes. Flame lengths and NOx concentrations were measured by varying flow velocities with and without installing quarls. Flame stabilities are significantly enhanced by oxyfuel combustion in contrast to air-fuel combustion. Flame length decreases with increasing fuel or oxygen velocity because of the enhancement of turbulent mixing. NOx concentration was reduced with increasing flo velocities. This can be attributed to the entrainment of inert product gases into flame decreasing flame temperature. The installation of quarl on the burners rather increased NOx concentration since the quarl blocked the entrainment above the nozzles.

• 지식경영연구
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• 제17권4호
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• pp.129-145
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• 2016

Nowadays, owing to the diffusion of smartphones and the growth of social networking services (SNS), the number of people who share their life with other SNS users by posting photos is increasing. The number of Instagram users has been particularly increasing since Instagram started its service in 2010. Compared to other SNS such as Facebook and Twitter, Instagram runs its service by focusing solely on photos, which is a major differentiation factor compared with other existing SNS. Previous studies, however, do not examine SNS that focus on photo sharing adequately. Therefore, we establish a hypothesis relating to the motivations behind a user's photo sharing attitude and posting intention through Instagram. Moreover, this will be achieved by employing TRA(Theory of Reasoned Action) and focusing on intrinsic and extrinsic motivations. The analysis results show that intrinsic motivation influences a user's sharing attitude and subjective norms. Apart from this, Instagram's expressivity influences a user's photo sharing attitude and posting intention.

• 한국IT서비스학회지
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• 제10권2호
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• pp.1-20
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• 2011

Due to the wide use of internet, electronic commerce market is gradually increasing but consumers still conceive various transaction-related problems. Various studies argue that those problems are obstructing trust in electronic commerce. Most studies on electronic commerce address that trust is measured as a Single dimension in which factors obstructing trust are same as those of increasing distrust. However, this study doesn't view trust as a single dimensional level but understands trust and distrust are bidimensional. This study also holds a viewpoint that they are influenced by different antecedents. According to the results of empirical analysis, the antecedents of trust have a significant explanatory power to trust and those of distrust have it to distrust. Other relations among the notions of trust and distrust, perceived risk and purchase intention as depicted in the research model are all statistically significant except the relation between distrust and purchase intention. This study shows a strong evidence of the bidimensionality of trust with separate antecedents.

• Tuberculosis and Respiratory Diseases
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• 제78권3호
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• pp.149-155
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• 2015

Extracorporeal life support (ECLS) is a type of cardiopulmonary bypass. It is an artificial means of supplying oxygen and removing $CO_2$ on behalf of damaged lungs while patients are recovering from underlying diseases. Recently, the use of ECLS is rapidly increasing as this machine becomes smaller, less invasive and easier to use. In addition, the improvement of clinicians' technique and outcome is increasing their application to patients with acute respiratory distress. In this regard, the purpose of this review is to introduce the physiological principles, risk factors, and advantages of ECLS, clinical rationale for using ECLS, ventilatory strategy during ECLS, which are still causing different opinions, the weaning from ECLS, and the use of anticoagulant.

• 한국세라믹학회지
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• 제45권5호
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• pp.251-255
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• 2008

Microwave dielectric properties of $MgTiO_3,\;MgWO_4,\;MgNb_2O_6$, and $MgTa_2O_6$ were investigated based on the structural characteristics. The dielectric constant (K) was dependent on the dielectric polarizabilities of the specimens, and the deviation of the observed dielectric polarizabilities (${\alpha}_{obs.}$) from the theoretical dielectric polarizabilities (${\alpha}_{theo.}$) were decreased with increasing of Mg-site bond valence. Quality factors (Qf) were affected by the sharing type of $MgO_6$ and $BO_6$ octahedra. Temperature coefficient of resonant frequency (TCF) was decreased with increasing of average octahedral distortion.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1993년도 가을 학술발표회 논문집
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• pp.35-38
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• 1993

Although bonding material content of the high strength flowing concrete is very important in engineering properties, in rich mix concrete increasing the bonding material content may not follow more good properties. This study is to investigate the influence of the bonding material content affecting on the engineering properties of high strength flowing concrete, and this paper is to analyze the properties of hardened concrete. The results reveal that the strength of concrete having loss bonding material content is higher than that of concrete having more bonding material content, and that in proportion to increasing of concrete strength brittleness factors decrease, and that the static modulus of elasticity in this study is less than that in specification.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2003년도 추계학술발표대회 논문집
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• pp.3-6
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• 2003

In this work, poly(ethylene oxide) nanofibers were fabricated by electrospinning to prepare nanofibers-reinforced composites. And the PEO powders-impregnated composites were also prepared to compare with physicochemical properties of nanofibers-reinforced composites. Morphology and fiber diameter of PEO nanofibers were determined by SEM observation. Mechanical interfacial properties of the composites were investigated in fracture toughness tests and interlaminar shear strength (ILSS) test. As a result, the fiber diameter decreased in increasing applied voltage. However the optimum condition for the fiber formation was 15 ㎸, resulting from increasing of jet instability at high voltage and the prepared PEO nanofibers were useful in fiber reinforced composites. The PEO-based nanofibers-reinforced composites showed an improvement of fracture toughness factors ($K_{IC} and G_{ IC}$) and ILSS, compared to the composites impregnated with PEO powders. These results were noted that the nanofibers had higher specific surface area and larger aspect ratio than those of the powder, which played an important role in improving the mechanical interfacial properties of the composites.