• Computers and Concrete
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• v.8 no.2
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• pp.177-192
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• 2011

This research paper aims at computer based modeling of carbonation induced corrosion under extreme conditions and its experimental verification by incorporating enhanced electrochemical and mass balance equations based on thermo-hygro physics with strong coupling of mass transport and equilibrium in micro-pore structure of carbonated concrete for which the previous research data is limited. In this paper the carbonation induced electrochemical corrosion model is developed and coupled with carbon dioxide transport computational model by the use of a concrete durability computer based model DuCOM developed by our research group at concrete laboratory in the University of Tokyo and its reliability is checked in the light of experiment results of carbonation induced corrosion mass loss obtained in this research. The comparison of model analysis and experiment results shows a fair agreement. The carbonation induced corrosion model computation reasonably predicts the quantitative behavior of corrosion rate for normal air dry relative humidity conditions. The computational model developed also shows fair qualitative corrosion rate simulation and analysis for various pH levels and coupled environmental actions of chloride and carbonation. Detailed verification of the model for the quantitative carbonation induced corrosion rate computation under varying relative conditions, different pH levels and combined effects of carbonation and chloride attack remain as scope for future research.

• Journal of Nutrition and Health
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• v.33 no.8
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• pp.833-839
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• 2000

The purpose of this study was to investigate sodium consumption and related psychosocial factors among hypertensive patients and normal adults through questionnaire development. The Theory of Planned Behavior provided the basis for the study. The mean blood pressure of subjects was 117. 1 mmHg/78.55mgHg in normal adults(N-218), 159.65mmHg/102.05mmHg(systolic/diastolic) in hypertensive group(N=219) and the sodium consumption was 5219.4${\pm}$1821.3mg in normal adults and 4631.4${\pm}$1749.1mg in hypertensive group. The results of Multiple logistic regression analysis showed that the odds of being hypetensive group were increasd as subjects felt that dalty food (OR=1.5) (OR=0.8). The odds of beign hypertensive group increased as subject received more support. With respect to perceived control, the odds of being hypertensive group were increased as subjects felt more confident in contolling salty intake when spouse likes to take salty food(OR=1.4). In contrast, subjects felt less confident in contolling sodium consumption when they took medicine(OR=0.8). Study findings revealed that all three factors, attitudes, subjective norms, and perceived control contributed to the model for explaining intentions, with subjective norms being most important. This findings provided the empirical evidence for the TPB in explaining salt intake. This study suggest that educational interventions for hypertension patients focus on changing sodium consumption through changing attitude toward high sodium consumption, subjective norms, perceived control over reducing sodium consumption of specific situations, specially subjective norms and perceived control. In addition, interventions may include strategies to change attitudes toward sodium consumption by helping hypertensive patients realize negative beliefs and modifying positive beliefs and to elicit and maintain subjective norm from doctors, family and neighbors, and to increase control beliefs for reducing sodium consumption.(Korean J Nutrition 33(8) : 833-839, 2000)

• Journal of Distribution Science
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• v.18 no.6
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• pp.25-35
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• 2020

Purpose:Travel agencies have use digital tools in order to shift the paradigm in how business is conducted. Online travel agencies provide the same services as a normal travel agency, including hotels, transportation, guided tours, reservations, and related services, but using an "online platform. Travelers planning a trip can use a lot of forms to collect information and have access to a larger amount of information, so the factors that influence the user's behavioral intention are very important. This research has the conducted to find what factors lead to the attitudes of consumers in using OTA using the UTAUT model. Research design, data and methodology: The object of this study were respondents of a google survey using convenient sample extraction method, chosen among consumers who gathered information, or purchased a product. A total of 217 of the 235 questionnaires Google survey answered were used in the final analysis, excluding insincere responses. Using PSS v.21 and AMOS v.21, frequency analysis, feasibility and reliability analysis, path analysis was performed. Results: UTAUT affects OTA use satisfaction and trust, and OTA satisfaction and trust affect behavior intention. Conclusions: Research was conducted using the UTAUT model to explore factors that affect the attitudes of users of online travel agencies (OTA).

• Journal of the Computational Structural Engineering Institute of Korea
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• v.22 no.3
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• pp.199-209
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• 2009

This paper deals with the three-dimensional finite element analysis of failure behavior of UHPFRC I-beam under monotonic load. Different from the constitutive law of normal and high strength concrete, an elastic-plastic fracture model that considers the tensile strain hardening is proposed to describe the material properties of UHPFRC. A multi-directional fixed crack criterion with tensile strain hardening is defined in the tensile region, and Drucker-Prager criterion with an associated flow rule is adopted in the compressive region. The influence of span, prestressing force and section on the behavior of UHPFRC I-beam are investigated. The comparison of the numerical results with the test results indicates a good agreement.

• Structural Engineering and Mechanics
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• v.50 no.6
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• pp.709-722
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• 2014

Ultra-High Performance Concrete (UHPC) is an innovative new material that, in comparison to conventional concretes, has high compressive strength and excellent ductility properties achieved through the addition of randomly dispersed short fibers to the concrete mix. This study presents the results of an experimental investigation on the behavior of axially loaded UHPC short circular columns wrapped with Carbon-FRP (CFRP), Glass-FRP (GFRP), and Aramid-FRP (AFRP) sheets. Six plain and 36 different types of FRP-wrapped UHPC columns with a diameter of 100 mm and a length of 200 mm were tested under monotonic axial compression. To predict the ultimate strength of the FRP-wrapped UHPC columns, a simple confinement model is presented and compared with four selected confinement models from the literature that have been developed for low and normal strength concrete columns. The results show that the FRP sheets can significantly enhance the ultimate strength and strain capacity of the UHPC columns. The average greatest increase in the ultimate strength and strain for the CFRP- and GFRP-wrapped UHPC columns was 48% and 128%, respectively, compared to that of their unconfined counterparts. All the selected confinement models overestimated the ultimate strength of the FRP-wrapped UHPC columns.

• Computers and Concrete
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• v.5 no.5
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• pp.435-448
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• 2008

Self-compacting concrete (SCC), characterized by the high flowability and resistance to segregation, is due to the high amount of paste (including cement and mineral admixtures) in contrast with normal concrete (NC). However, the high amount of paste will limit the volume fractions of coarse aggregate,and reduce the tendency of coarse aggregate to suppress drying shrinkage deformations. For this reason, SCC tends to produce higher values of drying shrinkage than NC for the most part. In order to assess the drying shrinkage of SCC quantitatively for application to offshore caisson foundations, the formulas presented in the literatures (ACI 209 and CEB-FIP) are used to predict the values of drying shrinkage in SCC according to the corresponding mix proportions. Additionally, a finite element (FE) model, which assumes concrete to be a homogeneous and isotropic material and follows the actual size and environmental conditions of the caisson, is utilized to simulate stress distribution situations and deformations in the SCC caisson resulting from the drying shrinkage. The probability of cracking and the behavior of drying shrinkage of the SCC caisson are drawn from the analytic results calculated by the FE model proposed in this paper.

• Steel and Composite Structures
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• v.8 no.2
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• pp.145-158
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• 2008

In slender sections there is a substantial post-buckling strength provided after the formation of local buckling waves. These waves happened due to normal stresses or shear stresses or both. In this study, a numerical investigation of the behavior of slender I-section beams in combined pure bending and shear has been described. The studied cases were assumed to be prevented from lateral torsional buckling. To achieve this aim, a finite element model that simulates the geometric and material nonlinear nature of the problem has been developed. Moreover, the initial geometric imperfections were included in the model. Different flange and web width-thickness ratios as well as web panel aspect ratios have been considered to draw complete set of interaction diagrams. Results reflect the interaction behavior between flange and web in resisting the combined action of moments and shear. In addition, the web panel aspect ratio will not significantly affect the combined ultimate shear-bending strength as well as the post local buckling strength gained by the section. Results are compared with that predicted by both the Eurocode 3 and the American Iron and Steel specifications, AISI-2001. Finally, an empirical interaction equation has been proposed.

• Earthquakes and Structures
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• v.20 no.1
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• pp.87-96
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• 2021

Ground motions recorded in near-fault sites, where the rupture propagates toward the site, are significantly different from those observed in far-fault regions. In this research, finite element modeling is used to investigate the effect of pile cap stiffness on the seismic response of soil-pile-structure systems under near-fault ground motions. The Von Wolffersdorff hypoplastic model with the intergranular strain concept is applied for modeling of granular soil (sand) and the behavior of structure is considered to be non-linear. Eight fault-normal near-field ground motion records, recorded on rock, are applied to the model. The numerical method developed is verified by comparing the results with an experimental test (shaking table test) for a soil-pile-structure system. The results, obtained from finite element modeling under near-fault ground motions, show that when the value of cap stiffness increases, the drift ratio of the structure decreases, whereas the pile relative displacement increases. Also, the residual deformations in the piles are due to the non-linear behavior of soil around the piles.

• Biomolecules & Therapeutics
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• v.24 no.5
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• pp.489-494
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• 2016

Neuropathic pain (NPP) is the main culprit among chronic pains affecting the normal life of patients. Procaine is a frequently-used local anesthesia with multiple efficacies in various diseases. However, its role in modulating NPP has not been reported yet. This study aims at uncovering the role of procaine in NPP. Rats were pretreated with procaine by intrathecal injection. Then NPP rat model was induced by sciatic nerve chronic compression injury (CCI) and behavior tests were performed to analyze the pain behaviors upon mechanical, thermal and cold stimulations. Spinal expression of Janus kinase 2 (JAK2) and signal transducer and activator of transcription 3 (STAT3) was detected by qRT-PCR and western blot. JAK2 was also overexpressed in procaine treated model rats for behavior tests. Results showed that procaine pretreatment improved the pain behaviors of model rats upon mechanical, thermal and cold stimulations, with the best effect occurring on the $15^{th}$ day post model construction (p<0.05). Procaine also inhibited JAK2 and STAT3 expression in both mRNA (p<0.05) and protein levels. Overexpression of JAK2 increased STAT3 level and reversed the improvement effects of procaine in pain behaviors (p<0.01). These findings indicate that procaine is capable of attenuating NPP, suggesting procaine is a potential therapeutic strategy for treating NPP. Its role may be associated with the inhibition on JAK2/STAT3 signaling.

• The Journal of the Korea Contents Association
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• v.19 no.1
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• pp.108-116
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• 2019

In this paper, we propose a method to apply artificial intelligence technology efficiently to integrated security control technology. In other words, by applying machine learning learning to artificial intelligence based on big data collected in integrated security control system, cyber attacks are detected and appropriately responded. As technology develops, many large capacity Is limited to analyzing individual logs. The analysis method should also be applied to the integrated security control more quickly because it needs to correlate the logs of various heterogeneous security devices rather than one log. We have newly proposed an integrated security service model based on artificial intelligence, which analyzes and responds to these behaviors gradually evolves and matures through effective learning methods. We sought a solution to the key problems expected in the proposed model. And we developed a learning method based on normal behavior based learning model to strengthen the response ability against unidentified abnormal behavior threat. In addition, future research directions for security management that can efficiently support analysis and correspondence of security personnel through proposed security service model are suggested.