• Tunnel and Underground Space
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• v.25 no.3
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• pp.244-254
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• 2015

The tunnel is excavated through the alluvial layer composed of sand and gravel with groundwater deposited on rock. A portion of upper part of the tunnel is located in the alluvial layer and there are several buildings just above the curved section of the tunnel. It is necessary to prevent from sand-flowing into the tunnel due to low strength of the alluvial, high groundwater level and shallow depth of the tunnel from the ground surface. For this, the alluvial around the tunnel is pre-reinforced by umbrella arch method with multi-stage grouting through large diameter steel pipes or jet grouting before excavating the tunnel. The effect of the pre-reinforcement of the tunnel and the safety of the buildings are monitored by measurement of ground deformation occurred during tunnelling.

• Tunnel and Underground Space
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• v.26 no.6
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• pp.466-474
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• 2016

Pre-reinforcement with umbrella arch grouting is conducted around a tunnel where a portion of the upper part of the tunnel is located in a sand and gravel layer. Surroundings of a first tunnel situated below groundwater table are reinforced with LW or SSM that is composed of ultra-fine cement and injected into multi-stages through large diameter steel pipes. With them, a first tunnel is safely excavated without both leaking of groundwater and fallings of sand and gravel from the arch. A second tunnel where groundwater is drained down to the bedrock is reinforced with jet grouting. The effect of the pre-grouting reinforcement is monitored by checking whether groundwater is dripping or sand or gravel is falling from the arch of the tunnels.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.27 no.12
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• pp.1053-1058
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• 2016

The eLoran(enhanced Long Range Navigation) transmitting antenna is analyzed for co-location with an AM transmitting antenna in an MF transmitting site. To compensate for the loading effect, the umbrella-type loading is applied for eLoran antenna. The validity of the co-location between the MF antenna and the eLoran antenna is verified through the simulation results of the radiation pattern and the return loss. Also, coupling including antenna matching circuit is analyzed to verify the effect of the transmitting circuit. The coupling between the LF and eLoran antenna is -53.3 dB at 100 kHz and -64.8 dB at 1,053 kHz, respectively.

• Journal of Plant Biotechnology
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• v.34 no.4
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• pp.293-298
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• 2007

Robinia pseudoacacia var. umbraculifera, commonly called umbrella black locust were regenerated after co-cultivation of internode segments with Agrobacterium tumefaciens which included yeast cadmium factor 1 (YCF 1) gene. The tolerance to cadmium and lead for plants can be increased by the YCF1 gene expression. Moreover, the recent studies have shown that YCF1 gene transgenic plants increase the accumulation of cadmium and lead into plant vacuoles. The effect of plant growth regulator such as 2,4-dichlorophenoxyacetic acid (2,4-D), ${\alpha}$-naphthaleneacetic acid (NAA), 6-benzyladenine (BA), and thidiazuron (TDZ) were studied to evaluate the propagation of plants through internode explants. The efficient induction of multiple adventitious shoots and callus were observed on a medium supplemented with 0.1 mg/L TDZ + 0.2 mg/L BA. To induce shoot elongation and rooting, regenerated shoots were transferred into basal MS medium without any plant growth regulator. Successful Agrobacterium tumefaciens mediated transformation was obtained by 20 min vacuum-infiltration with $50{\mu}M$ acetosyringone on the optimal multiple shoot induction medium with 30 mg/L hygromycin and 300 mg/L cefotaxime. To confirm the integration and expression of transgene, Polymerase Chain Reaction (PCR) and Reverse Transcriptase PCR (RT-PCR) were performed with specific primers. The frequency of transformation was approximately 18.94%. This study can be used to genetic engineering of phytoremediator.

• International journal of steel structures
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• v.18 no.5
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• pp.1525-1540
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• 2018

A test rig with multi-functional purposes was specifically designed and manufactured to study the behavior of multi-planar welded tubular joints subjected to multi-planar concurrent axial loading. An experimental investigation was conducted on full-scale welded tubular joints with each consisting of one chord and eight braces under monotonic loading conditions. Two pairs or four representative specimens (two specimens for each joint type) were tested, in which each pair was reinforced with two kinds of different internal stiffeners at the intersections between the chords using welded rectangular hollow steel sections (RHSSs) and the braces using rolled circular hollow steel sections (CHSSs) and welded RHSSs. The effects of different internal stiffeners at the chord-brace intersection on the load capacity of joints under concurrent multi-planar axial compression/tension are discussed. The test results of joint strengths, failure modes, and load-stress curves are presented. Finite element analyses were performed to verify the experimental results. The study results show that the two different joint types with the internal stiffeners at the chord-brace intersection under axial compression/tension significantly increase the corresponding ultimate strength to far exceed the usual design strength. The load carrying capacity of welded tubular joints decreases with a higher degree of the manufacturing imperfection in individual braces at the tubular joints. Furthermore, the interaction effect of the concurrent axial loading applied at the welded tubular joint on member stress is apparent.

• Journal of the Korean Geotechnical Society
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• v.22 no.6
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• pp.71-82
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• 2006

One of the most popular pre-reinforcement methods of tunnel heading in cohesionless soils would be the fore-polling of grouted pipes, known as RPUM (reinforced protective umbrella method) or UAM (umbrella arch method). This technique allows safe excavation even in poor ground conditions by creating longitudinal arch parallel to the tunnel axis as the tunnel advances. Some previous studies on the reinforcing effects have been performed using numerical methods and/or laboratory-based small scale model tests. The complexity of boundary conditions imposes difficulties in representing the tunnelling procedure in laboratory tests and theoretical approaches. Full-scale study to identify reinforcing effects of the tunnel heading has rarely been carried out so far. In this study, a large scale model testing for a tunnel in granular soils was performed. Reinforcing patterns considered are four cases, Non-Reinforced, Crown-Reinforced, Crown & Face-Reinforced, and Face-Reinforced. The behavior of ground and pipes as reinforcing member were fully measured as the surcharge pressure applied. The influences of reinforcing pattern, pipe length, and face reinforcement were investigated in terms of stress and displacement. It is revealed that only the Face-Reinforced has decreased sufficiently both vertical settlement in tunnel heading and horizontal displacement on the face. Vertical stresses along the tunnel axis were concentrated in tunnel heading from the test results, so the heading should be reinforced before tunnel advancing. Most of maximum axial forces and bending moments for Crown-reinforced were measured at 0.75D from the face. Also it should be recommended that the minimum length of the pipe is more than l.0D for crown reinforcement.

• The Journal of the Korea Contents Association
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• v.11 no.1
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• pp.254-265
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• 2011

The purpose of this study was to examine the effect of difficult endotracheal intubation education in the 119 rescue services. The subjects in this study were 60 members of the 119 rescue services that was under the umbrella of the Fire Service Headquarters of J province. A SPSS 14.0 program was utilized to find out the effect of tough tracheal intubation education on their relevant knowledge, self-confidence, academic self-efficacy and technical Performance in consideration of general characteristics. The findings of the study were as follows: 1. They showed a significant improvement in all the knowledge, self-confidence, academic self-efficacy and technical Performance after they received that education. 2. As for connections between general characteristics and knowledge before and after that education, there were significant differences in their knowledge according to gender and career of working in the hospital, and their rank and career of working in the hospital made a significant differences to their self-confidence. Their academic self-efficacy significantly differed with rank, career of working in the hospital and academic credential. There were significant gaps among them technical Performance Case 1 according to career of working in the 119 rescue services, and technical Performance Case 2 significantly varied with age and academic credential. There were significant gaps in technical Performance Case 3 according to career of working in the 119 rescue services and career of working in the hospital after that education was provided, and technical Performance Case 4 significantly varied with age and rank before and after the education was conducted. In conclusion, the kind of education programs that aim at stirring up the interest of the 119 rescue services in advanced airway and helping the members learn about tracheal intubation accurately with confidence is urgently required.

• Journal of Korea Society of Industrial Information Systems
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• v.27 no.3
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• pp.21-28
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• 2022

Fine dust enters the lungs or blood vessels through the respiratory tract through the air. Recently, due to the fine dust problem, the demand for air purifiers in Korea is also increasing rapidly. Moss is the oldest terrestrial plant, and it is known that it has the property of adsorbing and decomposing heavy metals and fine dust. To compare the effect of reducing fine dust between moss and the existing chemical filter (Hepa), a cube of 1 m³ was manufactured and the amount of fine dust reduction under a controlled environment was compared. Under the fine dust conditions, an umbrella moss filter, rat tail moss filter, feather moss filter, and silk moss filter were inserted for a total of 40 experiments, 10 times each in 4 different situations. The difference between the amount after 30 minutes was statistically significant for all filters. However, as a result of the test, it was confirmed that there was no statistically significant difference between filters for fine dust, mixed gas, CO₂, and O₂. In particular, it was confirmed that the previously claimed effect of oxygen generation was almost nonexistent. Through this result, it was confirmed that the reduction of fine dust is effective regardless of the species view of moss, and it is expected to replace or supplement the chemical filter of the existing air purifier through future improvement.

• Asia Marketing Journal
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• v.15 no.3
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• pp.97-115
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• 2013

This paper was motivated by two gaps in the extant literature on brand portfolio planning. First, research has shown that, as the number of products connected to a brand increases, the extended product receives more favorable evaluations. However, this result was obtained by comparing two brands with different number of products while controlling the brands' breadths. Hence one may question if the above result would hold when the brand is narrow as well as broad. Second, the literature has investigated the effect of brand breadth on the perceived fit and evaluations of an extended product within a relatively limited range ("narrow vs. broad") and not considered the case of a "very broad" brand. To address these gaps, we propose two hypotheses: 1) the effects of the number of products associated with a brand on the perceived fit and evaluations of a moderately far brand extension are moderated by the brand's breadth (H1); and 2) the relationship between a brand's breadth and a moderately far extension's perceived fit and evaluations looks like an inverse-U shape (H2). Study 1 was conducted to test H1. Study 1 employed a 2 × 2 within-subjects design in which the first factor was the number of products (small (2) or large (5)), and the second factor was brand breadth (narrow or broad). We measured brand breadth as the perceived similarity among products associated with a brand. Participants provided the perceived fit and evaluations of an extended product. Study 2 was conducted to test H2 as well as to replicate Study 1 in a more general setting and with different products. It employed a 2 × 3 within-subjects design, in which the first factor was the number of products (small (2) or large (5)), and the second factor was brand breadth (narrow, broad, or very broad). The results from two experiments support both hypotheses. This paper contributes to the literature on brand extensions in two ways. First, it broadens our understanding of the effects of product number and brand breadth on extended product evaluations by considering the two factors jointly. Second, we believe this study to be the first to present evidence that brand breadth can exert an inverted U-shape effect on the perceived fit and evaluations of an extended product. The results also offer implications for marketers. First, marketers should heed the finding that adding similar products to a narrow brand does not help the brand's extension launch. Second, the finding that the relationship between brand breadth and extended product evaluations might not be linear provides practical implications. While a narrow brand should not keep launching close extensions, nor should a broad brand continue producing far extensions to broaden its breadth. A firm with a broad corporate or family brand might want to consider introducing a new brand instead of adding dissimilar products under the brand umbrella.

• Journal of Korean Dental Science
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• v.16 no.2
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• pp.128-148
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• 2023

Dementia is an umbrella term that describes the loss of thinking, memory, attention, logical reasoning, and other mental abilities to the extent that it interferes with the activities of daily living. More than 50 million individuals worldwide live with dementia, which is expected to increase to 131 million by 2050. Recent research has shown that poor oral health increases the risk of dementia, while oral health declines with cognitive decline. In this narrative review, the literature was based on the "hypothesis" that dementia and oral health have a close relationship, and appropriate oral health and occlusal rehabilitation treatment can improve the quality of life of patients with dementia and prevent progression. We conducted a literature search in PubMed and Google Scholar databases, using the search terms "dementia," "major neurocognitive disorder," "dentition," "occlusion," "tooth loss," "dental prosthesis," "dental implant," and "occlusal rehabilitation" in the title field over the past 30 years. A total of 131 studies that scientifically addressed dementia, oral health, and/or oral rehabilitation were included. In a meta-analysis, the random effect model demonstrated significant tooth loss increasing the dementia risk 3.64-fold (pooled odds ratio=3.64, 95% confidence interval [2.50~5.32], P-value=0.0348). Tooth loss can be an important indicator of cognitive function decline. As the number of missing teeth increases, the risk of dementia increases. Loss of teeth can lead to a decrease in the ascending information to the brain and reduced masticatory ability, cerebral blood flow, and psychological atrophy. Oral microbiome dysbiosis and migration of key bacterial species to the brain can also cause dementia. Additionally, inflammation in the oral cavity affects the inflammatory response of the brain and the complete body. Conversely, proper oral hygiene management, the placement of dental implants or prostheses to replace lost teeth, and the restoration of masticatory function can inhibit symptom progression in patients with dementia. Therefore, improving oral health can prevent dementia progression and improve the quality of life of patients.