• Physical Therapy Rehabilitation Science
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• v.9 no.1
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• pp.49-54
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• 2020

Objective: The purposes of this study was to evaluate the diagnostic values of abdominal muscles thickness and sterno-costal angle as the quantitative diagnostic indicators for young adults with rounded shoulders. Design: A observational, cross-sectional study. Methods: This study included thirty-three male participants in order to examine the relationship among thoracic kyphosis, sternocostal angle, and abdominal muscle thickness. We used ultrasound imaging to measure the muscle thickness, two gravity-dependent inclinometers to measure the kyphosis angle, and Image J to measure the sterno-costal angle. Results: There was a significant positive correlation between the amount of thoracic kyphosis angle and muscle thickness of the external oblique (EO) on the right side (r=0.931), and on the left side (r=0.432), and the transverse abdominis (TrA) (r=0.649). There was also a significant negative correlation between the thoracic kyphosis angle and the sterno-costal angle at the right side (r=-0.942) and at the left side (r=-0.860). There was a significant positive relationship with muscle thickness of the EO and TrA on the right side with the thoracic kyphosis angle, and was significant negative relationship with the sterno-costal angle on both sides. Conclusions: The results of the study suggest that the thoracic kyphosis angle is related to muscle thickness of the EO and TrA on the dominant side and the sterno-costal angle. We also suggest that future studies are needed to determine how strengthening the abdominal muscles may contribute to preventing excessive thoracic kyphosis in young adults.

• Corrosion Science and Technology
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• v.13 no.5
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• pp.178-185
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• 2014

Alloy 617 is considered as a candidate Ni-based superalloy for the intermediate heat exchanger (IHX) of a very high-temperature gas reactor (VHTR) because of its good creep strength and corrosion resistance at high temperatures. Helium is used as a coolant in a VHTR owing to its high thermal conductivity, inertness, and low neutron absorption. However, helium inevitably includes impurities that create an imbalance in the surface reactivity at the interface of the coolant and the exposed materials. As the Alloy 617 has been exposed to high temperatures at $950^{\circ}C$ in the impure helium environment of a VHTR, the degradation of material is accelerated and mechanical properties decreased. The high-temperature strength, creep, and corrosion properties of the structural material for an IHX are highly important to maintain the integrity in a harsh environment for a 60 year period. Therefore, an alloy superior to alloy 617 should be developed. In this study, the mechanical and high-temperature corrosion properties for Ni-Cr alloys fabricated in the laboratory were evaluated as a function of the grain boundary strengthening and alloying elements. The ductility increased and decreased by increasing the amount of Mo and Cr, respectively. Surface oxide was detached during the corrosion test, when Al was not added to alloy. However the alloy with Al showed improved oxide adhesive property without significant degradation and mechanical property. Aluminum seems to act as an anti-corrosive role in the Ni-based alloy.

• Transactions of the Korean hydrogen and new energy society
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• v.30 no.1
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• pp.83-94
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• 2019

LPG is increasingly being used as a clean energy source due to the continuous strengthening of environmental regulations. In addition, the demand of propane which is the basic compound for petrochemicals is increasing for propylene production. In the study, a divided wall column was used as de-propanizer and de-butanizer, which is expected to save large amount of energy among the four conventional distillation columns used for processing LPG. The simulation results showed a decrease of energy duty with ESI by 30.30% using two divided wall columns. Furthermore, simulation case studies were carried out with respect to design and operation condition. The main column tray and withdrawal tray were determined from the design case studies while the internal liquid flow and vapor flow were decided from the operating case studies. Also, ESI of 1.06% could be achieved from the case studies. According to the results, the simulation method used showed that it is greatly helpful to the design and evaluate a highly efficient divided wall column.

• Journal of Convergence for Information Technology
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• v.11 no.1
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• pp.12-19
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• 2021

For strengthening the national defense, the function of tactical network is essential. tactics and strategies in wartime situations are based on numerous information. Therefore, various reconnaissance devices and resources are used to collect a huge amount of information, and they transmit the information through tactical networks. In tactical networks that which use contention based channel access scheme, high-speed nodes such as recon aircraft may have performance degradation problems due to unnecessary channel occupation. In this paper, we propose a learning-backoff method, which empirically learns the size of the contention window to determine channel access time. The proposed method shows that the network throughput can be increased up to 25% as the number of high-speed mobility nodes are increases.

• Atmosphere
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• v.17 no.1
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• pp.55-68
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• 2007

Future climate changes over East Asia are projected by anthropogenic forcing of greenhouse gases and aerosols using ECHO-G/S (ECHAM4/HOPE-G). Climate simulation in the 21st century is conducted with three standard SRES scenarios (A1B, B1, and A2) and the model performance is assessed by the 20th Century (20C3M) experiment. From the present climate simulation (20C3M), the model reproduced reliable climate state in the most fields, however, cold bias in temperature and dry bias of summer in precipitation occurred. The intercomparison among models using Taylor diagram indicates that ECHO-G/S exhibits smaller mean bias and higher pattern correlation than other nine AOGCMs. Based on SRES scenarios, East Asia will experience warmer and wetter climate in the coming 21st century. Changes of geographical patterns from the present to the future are considerably similar through all the scenarios except for the magnitude difference. The temperature in winter and precipitation in summer show remarkable increase. In spite of the large uncertainty in simulating precipitation by regional scale, we found that the summer (winter) precipitation at eastern coast (north of $40^{\circ}N$) of East Asia has significantly increased. In the 21st century, the warming over the continents of East Asia showed much more increase than that over the ocean. Hence, more enhanced (weakened) land-sea thermal contrast over East Asia in summer (winter) will cause strong (weak) monsoon. In summer, the low pressure located in East Asia becomes deeper and the moisture from the south or southeast is transported more into the land. These result in increasing precipitation amount over East Asia, especially at the coastal region. In winter, the increase (decrease) of precipitation is accompanied by strengthening (weakening) of baroclinicity over the land (sea) of East Asia.

• Composites Research
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• v.17 no.5
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• pp.54-60
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• 2004

A new three-dimensional model for predicting the relationship between the prestrain of the composite and the amount of phase transformation of shape memory alloy inducing shape memory effect has been proposed by using Eshelby's equivalent inclusion method with Mori-Tanaka's mean field theory. The model composite is aluminum matrix reinforced with short TiNi fiber shape memory alloy, where the matrix is work-hardening material of power-law type. The analytical results predicted by the current model show that most of the prestrain is induced by the plastic deformation of the matrix, except the small prestrain region. The strengthening mechanism of the composite by the shape memory effect should be explained by excluding its increase of yield stress due to the work-hardening effect of the matrix.

• Journal of Software Engineering Society
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• v.25 no.1
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• pp.11-18
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• 2012

Characteristic of decommissioning target facility investigate and understand is very important. because radioactive materials occurs in the decommissioning and dismantling, so it is difficult to use a general dismantling method. Decommissioning nuclear facilities, the characteristics of the target of research to predict the amount of decommissioning waste, decommission projects costing is largely utilized. For this purpose, we developed DEFACS(Decommissioning Facility Characterization DB System) that manage characteristic of decommissioning target facility. But nuclear facility decommissioning takes long time. so we inevitably developed system during decommissioning works, it occurs many system changes. For this reason, it is difficult to apply general development process, so we take CBD process that divide CD(Component Development) and CBSD(Component Based Software Development) for handling change of requirement. it make Component of the overall system for changes to minimize changes by strengthening the independence of components and processes due to changes in requirements were to minimize stopping of the process.

• Journal of the Korea institute for structural maintenance and inspection
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• v.23 no.2
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• pp.92-98
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• 2019

In general, high strength and high performance fiber reinforced cement composites exclude coarse aggregates basically in order to have homogeneous distributions of material properties. However, these fiber-reinforced cement mortar without coarse aggregate have a tenancy that the modulus of elasticity is low and the unit weight of cement is high, resulting in low economic efficiency. Therefore, in this study, the development of high ductile fiber - reinforced concrete was conducted, which has the adequate level of coarse aggregate but still retains the high flexural toughness and strength and also has the crack - distributing performance. Experimental study was carried out by using the amount of coarse aggregate as an experimental parameter. The results showed that the best flexural toughness and crack dispersion characteristics was obtained when the coarse aggregate was added at 25% by weight of the fine aggregate to the typical mixtures of high ductile cement mortar. PVA fiber was effective in crack distribution and ductility enhancement, and steel fiber was effective in strengthening flexural strength rather than crack distribution.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.153-156
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• 2008

The objective of the present study is to evaluate the flexural behavior of reinforced concrete columns externally strengthened with wire rope and T-shape steel plate units. Three strengened columns and a control unstrengthened column were tested under cyclic lateral load simultaneously subjected to a constant axial load. All columns had same section size, and the arrangement of longitudinal reinforcement and internal hoop. The spacing of wire rope range from 40 ${\sim}$ 80mm, which corresponds from 1.0 ${\sim}$ 0.5, respectively, times the minium amount of hoop specified in seismic design of ACI 318-05. Test results showed that the proposed unbonded-type strengthening procedure is very effective for improving the flexural ductility of reinforced concrete columns.

• Journal of Korea Water Resources Association
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• v.37 no.2
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• pp.109-119
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• 2004

This research is an analysis of the water vapor transport change Into the continent due to the global warming effect with the general circulation models. Water vapor transport change from ocean to land increases through the year due to CO2 doubling effect. In Eurasia, it indicates an increase about 170∼350${\times}$06 Mt/day the whole year. In Africa, it shows an decrease every month except November, especially there is the maximum decrease about -350${\times}$106 Mt/day during August-September. In other continents, excluding Eurasia and Africa, the change of water vapor transport vary with the month below $\pm$8.0${\times}$106 Mt/day with the unsystematic patterns. In Eurasia, the change of water vapor transport increases as a whole, but it decrease in desert areas which occupy a high area-ratio. Therefore, except desert areas, the amount of the growth in water vapor transport change concentrate on Asian monsoon area. As a result of monsoon strengthening, available water will grow considerably at the asian monsoon areas.