• Advances in nano research
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• v.7 no.3
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• pp.181-190
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• 2019

The thermal buckling temperature values of the graded carbon nanotube reinforced composite shell structure is explored using higher-order mid-plane kinematics and multiscale constituent modeling under two different thermal fields. The critical values of buckling temperature including the effect of in-plane thermal loading are computed numerically by minimizing the final energy expression through a linear isoparametric finite element technique. The governing equation of the multiscale nanocomposite is derived via the variational principle including the geometrical distortion through Green-Lagrange strain. Additionally, the model includes different grading patterns of nanotube through the panel thickness to improve the structural strength. The reliability and accuracy of the developed finite element model are varified by comparison and convergence studies. Finally, the applicability of present developed model was highlight by enlighten several numerical examples for various type shell geometries and design parameters.

• Advances in concrete construction
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• v.15 no.4
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• pp.269-286
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• 2023

In the present study, we aim to utilize the numerical solution frequency results of functionally graded beam under thermal and dynamic loadings to train and test an artificial neural network. In this regard, shear deformable functionally-graded beam structure is considered for obtaining the natural frequency in different conditions of boundary and material grading indices. In this regard, both analytical and numerical solutions based on Navier's approach and differential quadrature method are presented to obtain effects of different parameters on the natural frequency of the structure. Further, the numerical results are utilized to train an artificial neural network (ANN) using AdaGrad optimization algorithm. Finally, the results of the ANN and other solution procedure are presented and comprehensive parametric study is presented to observe effects of geometrical, material and boundary conditions of the free oscillation frequency of the functionally graded beam structure.

• Steel and Composite Structures
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• v.44 no.6
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• pp.829-843
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• 2022

This manuscript work presents a comprehensive continuum model capable to investigate the effect of porosity on vibro-acoustic behaviour of functionally graded (FG) beams resting on an elastic foundation subjected to thermal and mechanical loadings. Effects of uniform temperature rise and edge compressive load on the sound radiation characteristics are studied in a comparative manner. The numerical analysis is carried out by combining finite element method with Rayleigh's integral. Detailed parametric studies are accomplished, and influences of power law index, porosity volume, porosity distribution and boundary conditions on the vibro-acoustic response characteristics are analyzed. It is found that the vibro-acoustic response under mechanical edge compression is entirely different compared to from that under the thermal load. Furthermore, nature of grading of porosity affects the sound radiation behaviour for both the loads. The proposed model can be used to obtain the suppression performance of vibration and noise FG porous beams under thermal and mechanical loads.

• Journal of radiological science and technology
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• v.32 no.4
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• pp.461-469
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• 2009

To predict the tumor grading, various imaging modalities have been applied clinically. This study determines clinical usefulness of perfusion MRI, using relative cerebral blood volume in grading of the gliomas. We did a retrospective review of 17 patients (mean age, 57.5 years; 11 male, 6 female) who underwent perfusion MR and conventional MRI, and then correlated pathologically after operation. Statistical analysis of regional cerebral blood volume and relative cerebral blood volume(rCBV) was performed by using softwares such as PAT by SIEMENS and Xmap ver 2.0 developed by ourselves. Six patients out of 13 were low-grade gliomas while eleven patients were the high-grade gliomas. Mean relative CBV (m_rCBV/white matter) in the low-grade gliomas was 1.62, and mean relative CBV(m_rCBV/cortex) was 0.12. In the high-grade gliomas, mean relative CBV(m_rCBV/white matter) and mean relative CBV(m_rCBV/cortex) were 33.53 and 0.96. Mean relative CBV of gliomas were elevated with a statistical difference(P<.05), compared with contralateral white matter(P=.019) or cortex(P=.025). Furthermore mean relative CBV(m_rCBV/white matter) was much higher than mean relative CBV(m_rCBV/cortex). Perfusion MRI using regional cerebral blood volume and rCBV is very useful imaging modality for grading the glioma.

• Journal of the Korean Wood Science and Technology
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• v.43 no.4
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• pp.446-455
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• 2015

Based on comparative studies on standards and grading procedures of machine graded lumber in Korea and other countries, this study proposed a procedure of determining the grade classification and design strengths of domestic machine graded lumber. Differences between machine stress rated lumber and E-rated laminations were detailed in order to clarify the need for the procedure improvement. To this improvement the use of average MOE requirement for grading was introduced instead of the fixed minimum MOE requirement which is currently used in the Korean standards. It was found that the fixed minimum MOE requirement method was easier for an inspector to grade but, less efficient as a strength predictor than the average MOE requirement method. The advantage of average MOE requirement method is statistically MOR-MOE regression-based MOR prediction and highly efficient in quality control though it requires a computer-aided operation system in an initial setup. A major weakness of the current Korean grading system was found that different strength characteristics depending on wood species were not reflected on the grade classification and the tabulated allowable design stress. The proposed procedures were developed taking advantages of respective merits of both methods and based on MOR-MOE regression analysis. Through this procedure, the grades of machine stress rated lumber should be revised to become interchangeable with E-rated lamination, which would be beneficial to the cost competitiveness of domestic machine graded lumber and glued laminated timber industry.

• Smart Structures and Systems
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• v.21 no.4
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• pp.493-519
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• 2018

This article presents a finite element (FE) model to assess the free vibration and static response of a functionally graded skew magneto-electro-elastic (FGSMEE) plate. Through the thickness material grading of FGSMEE plate is achieved using power law distribution. The coupled constitutive equations along with the total potential energy approach are used to develop the FE model of FGSMEE plate. The transformation matrix is utilized in bringing out the element matrix corresponding to the global axis to a local axis along the skew edges to specify proper boundary conditions. The effect of skew angle on the natural frequency of an FGSMEE plate is analysed. Further, the study includes the evaluation of the static behavior of FGSMEE plate for various skew angles. The influence of skew angle on the primary quantities such as displacements, electric potential, and magnetic potential, and secondary quantities such as stresses, electric displacement and magnetic induction is studied in detail. In addition, the effect of power-law gradient, thickness ratio, boundary conditions and aspect ratio on the free vibration and static response characteristics of FGSMEE plate has been investigated.

• Annals of Clinical Neurophysiology
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• v.15 no.1
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• pp.1-6
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• 2013

Background: Bell's palsy (BP) is the most common cause of unilateral lower motor facial palsy. Recurrent paralysis of the facial nerve is unusual and reported in only 7-8%. Methods: A total of 394 consecutive patients with acute BP patients were enrolled at Daegu Catholic University Hospital from July 2005 to September 2012. We classified the patients into two groups-single BP and recurrent BP-and compared them by patient characteristics, clinical features, MRI findings, electrophysiologic findings and prognosis. The degree of BP was graded according to the House and Brackmann facial nerve grading system. Results: Recurrent BP was observed in 31 (7.9%) patients. The number of recurrence was varied from 2 to 5. The recurrent BP (9.7%) had more incidence of family history and MRI enhancement than those of single BP (2.2%, p=0.047). The single BP (63.4%) had better recovery than recurrent BP (45.2%, p=0.045). Conclusions: The recurrent BP had more incidence of family history, MRI enhancement and poor prognosis than the single BP.

• Annals of Clinical Neurophysiology
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• v.10 no.1
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• pp.38-42
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• 2008

Background: Idiopathic facial nerve palsy, or Bell's palsy (BP), is a common and important disease. Recurrent Bell's palsy has been known as a rare entity with only a few cases in the literature. Methods: A total of 111 consecutive patients with acute BP patients were enrolled at Daegu Catholic University Hospital from July 2005 to March 2007. We classified the patients into two groups - single BP and recurrent BP - and compared them by demographic data, clinical features, MRI findings and prognosis. The degree of BP was graded according to the House and Brackmann facial nerve grading system. Results: Recurrent BP was observed in 10 (9%) patients. The number of recurrence was varied from 2 to 5. The mean age of first attack in recurrent BP was $35.70{\pm}23.65$ years old and was earlier than that of the single BP ($50.94{\pm}16.21$ year). The larger proportion of the single BP had an abnormal enhancement of affected facial nerve (91.3%) than the recurrent BP (50%). The recurrent BP showed worse prognosis than the single BP. The associated conditions, etiology, and clinical features were similar between two groups. Conclusions: In comparison with single BP, recurrent BP showed earlier onset of first BP attack, less frequent abnormal enhancement of facial nerve on MRI, and worse prognosis.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 2008.11a
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• pp.458-463
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• 2008

This study focused on the suggestion that is improved alternation with relation to construction item & assurance term in order to deal with the assurance conflict efficiently which have been happened in the apartment housing. To correspond to this purpose of research, as a first step, we introduced the add item & sub item of construction work on the basis upon construction specifications of the number of 17 on housing law as a alternation of the defects assurance construction item that is necessary to correct as soon as possible. As a second step of the research, we did cross analysis & compare the result of defects happened to the apartment housing complex of 293 with the defect' rate of construction work excepted from the supervisory item, and main performance estimation items in the HPGS(House Performance Grading System), and analysis results introduced from question survey. As the result of this research work, we became to reflect the improving schemes on the housing Law the year of 2007.

• The Journal of Asian Finance, Economics and Business
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• v.7 no.4
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• pp.317-324
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• 2020

The study aims to analyze the theoretical background of the economic growth and sustainable development; systematization of scientists view on monitoring and economic and innovative evaluation, analysis and diagnosis of factors affecting these processes. Rating characteristics of the level of innovative resources development obtained based on the comparative analysis of Kazakhstan regions. Calculations were done based on official statistics during 2010 and 2015-2017. Based on obtained data there has been grading of the country regions and their ratings were determined by the level of development of innovative resources. This research identifies areas and mechanisms to ensure balanced sustainable development of the national economy. The findings suggest that sustainable development of the state is affected by the innovative activity of the regions, the sustainable development of which is ensured by innovative enterprises. Transition to the model of sustainable territorial development involves the formation of such conditions and the use of mechanisms under which the natural base of this development is not destroyed, the environment suitable for human existence is preserved and reproduced. The findings of this research support for pursuing a national policy of reducing regional imbalances, and promoting a more balanced and sustainable development of the whole country.