• Korean Architects
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• s.509
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• pp.97-97
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• 2011

• Korean Architects
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• s.517
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• pp.88-89
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• 2012

• Korean Architects
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• s.508
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• pp.92-93
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• 2011

• Korean Architects
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• s.519
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• pp.104-105
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• 2012

• Structural Engineering and Mechanics
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• v.72 no.1
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• pp.113-129
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• 2019

A four-variable shear deformation refined plate theory has been proposed for dynamic characteristics of smart plates made of porous magneto-electro-elastic functionally graded (MEE-FG) materials with various boundary conditions by using an analytical method. Magneto-electro-elastic properties of FGM plate are supposed to vary through the thickness direction and are estimated through the modified power-law rule in which the porosities with even and uneven type are approximated. Pores possibly occur inside functionally graded materials (FGMs) due the result of technical problems that lead to creation of micro-voids in these materials. The variation of pores along the thickness direction influences the mechanical properties. The governing differential equations and boundary conditions of embedded porous FGM plate under magneto-electrical field are derived through Hamilton's principle based on a four-variable tangential-exponential refined theory which avoids the use of shear correction factors. An analytical solution procedure is used to achieve the natural frequencies of embedded porous FG plate supposed to magneto-electrical field with various boundary condition. A parametric study is led to carry out the effects of material graduation exponent, coefficient of porosity, magnetic potential, electric voltage, elastic foundation parameters, various boundary conditions and plate side-to-thickness ratio on natural frequencies of the porous MEE-FG plate. It is concluded that these parameters play significant roles on the dynamic behavior of porous MEE-FG plates. Presented numerical results can serve as benchmarks for future analyses of MEE-FG plates with porosity phases.

• Coupled systems mechanics
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• v.2 no.1
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• pp.1-22
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• 2013

Under thermal environment, Magneto-Electro-Elastic (MEE) material exhibits pyroelectric and pyromagnetic effects which can be used for enhancing the performance of MEE sensors. Recently studies have been published on material constants such as pyroelectric constant and pyromagnetic constant for magneto-electro-thermo-elastic smart composite. Hence, the main aim of this paper is to study the pyroelectric and pyromagnetic effects on behavior of MEE plate under different boundary conditions subjected to uniform temperature. A numerical study is carried out using eight noded brick finite element under uniform temperature rise of 100 K. The study focused on the pyroelectric and pyromagnetic effects on system parameters like displacements, thermal stresses, electric potential, magnetic potential, electric displacements and magnetic flux densities. It is found that, there is a significant increase in electric potential due to the pyroelectric and pyromagnetic effects. These effects are visible on electric and magnetic potentials when CFFC and FCFC boundary conditions are applied. Additionally, the pyroelectric and pyromagnetic effects at free edge is dominant (nearly thrice the value in CFFC in comparison with FCFC) than at middle of the plate. This study is a significant contribution to sensor applications.

• Advances in nano research
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• v.4 no.2
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• pp.65-84
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• 2016

This paper investigates the buckling behavior of shear deformable piezoelectric (FGP) nanoscale beams made of functionally graded (FG) materials embedded in Winkler-Pasternak elastic medium and subjected to an electro-magnetic field. Magneto-electro-elastic (MEE) properties of piezoelectric nanobeam are supposed to be graded continuously in the thickness direction based on power-law model. To consider the small size effects, Eringen's nonlocal elasticity theory is adopted. Employing Hamilton's principle, the nonlocal governing equations of the embedded piezoelectric nanobeams are obtained. A Navier-type analytical solution is applied to anticipate the accurate buckling response of the FGP nanobeams subjected to electro-magnetic fields. To demonstrate the influences of various parameters such as, magnetic potential, external electric voltage, power-law index, nonlocal parameter, elastic foundation and slenderness ratio on the critical buckling loads of the size-dependent MEE-FG nanobeams, several numerical results are provided. Due to the shortage of same results in the literature, it is expected that the results of the present study will be instrumental for design of size-dependent MEE-FG nanobeams.

• Advances in nano research
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• v.14 no.1
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• pp.27-43
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• 2023

This article investigates the energy harvesting characteristics of a magneto-electro-elastic (MEE) cantilever beam reinforced with carbon nanotubes (CNT) under transverse vibration. To this end, the well-known lumped parameter model is used to represent the coupled multiphysics problem mathematically. The proposed system consists of the MEE-CNT layer on top and an inactive substrate layer at the bottom. The substrate is considered to be made of either an isotropic or composite material. Basic laws such as Gauss's Law, Newton's Law and Faraday's Law are used to arrive at the governing equations. Surface electrodes across the beam are used to harvest the electric potential produced, together with a wound coil, for the generated magnetic potential. The influence of various distributions of the CNT and its volume fraction, substrate material, length-to-thickness ratio, and thickness ratio of substrate to MEE layer on the energy harvesting behaviour is thoroughly discussed. Further, the effect of external resistances and changes in substrate material on the response is analysed and reported. The article aims to explore smart material-based energy harvesting systems, focusing on their behaviour when reinforced with carbon nanotubes. The results of this study may lead to an improved understanding of the design and analysis of CNT-based smart structures.

• Journal of Pharmacopuncture
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• v.9 no.3 s.21
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• pp.105-116
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• 2006

Objectives : To investigate the effect of Ga-mee-Gwui-ryong-tang herbal acupuncture(GR-HA) at GB39 and ST36 and the effect of Yuk-mee-ji-hwang-tang herbal acupuncture(YM-HA) at GB39 and KI10 on growth in mice. Methods : Mice were divided into 7 group(n=10) ; saline-ST36, saline-GB39 and KI10, GR-HA-ST36 group treated with GR-HA at right ST36, GR-HA-GB39 group treated with GR-HA at right GB39, YM-HA-GB39 group treated with YM-HA at right GB39, YM-HA-KI10 group treated with YM-HA at right KI10. Saline-ST36 group, saline-GB39 group and saline-KI10 group were injected with saline at right ST36, GB39, KI10 respectively. Saline injection and HA were performed 3 times a week for 18 days. The length(total height, body length and tail length), weight and the protein efficiency ratio were measured as well as IGF-1 level in serum. Results : 1. GR-HA at GB39 and GR-HA at ST36 promoted growth in weight, tail length and total height but there was no statistical significance. 2. GR-HA at GB39 significantly promoted protein efficiency on the 14th day and GR-HA at ST36 on the 3rd day. 3. GR-HA at GB39 significantly increased serum IGF-1. GR-HA at ST36 increased IGF-1 slightly but with no statistical significance. 4. YM-HA at GB39 and YM-HA at KI10 promoted growth in weight, height, tail length and total height but there was no statistical relevance. 5. YM-HA at GB39 and YM-HA at KI10 significantly promoted protein efficiency on the 14th day. 6. YM-HA at GB39 and YM-HA at KI10 significantly increased serum IGF-1. Serum IGF-1 level of YM-HA-KI10 group was significantly higher than that of YM-HA-GB39 group. 7. Serum IGF-1 level of GR-HA-GB39 group was significantly higher than that of YM-HA-GB39 group. Conclusions : GR-HA and YM-HA both may promote growth. This study suggests that herbal acupuncture at GB39 is more effective with Gwui-ryong-tang than Yuk-mee ji-hwang-tang to promote growth. It also suggests that Yuk-mee ji-hwang-tang herbal acupuncture is more effective at KI10 than at GB39.

• Proceedings of the KOR-BRONCHOESO Conference
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• 1982.05a
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• pp.15.1-15
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• 1982

Clinical findings for 95 patients (159 ears) of MEE (middle ear effusion) treated at Wallace Memorial Baptist Hospital (Busan) from July 1979 to August 1981 were observed. A group who was treated with myringotomy and ventilation tube isertion was compared with another group of children treated with adenotonsillectomy at the same time. The following are the results: 1) The sex distribution showed 48 male and 47 female, and the age distribution was most common in the ages from six to ten (34 cases, 35%). 2) MEE of children treated with adenotonsillectomy in the same duration was 18 cases (14%), and it was 19% of all MEE patients. 3) Bilateral effusion (67%) was as twice as unilateral cases (33%). In children, bilateral effusion (42 cases, 88%) was predominant, and MEE in adenotonsillectomized children was bilateral in all cases. 4) The nature of middle ear fluid was 49% serous exudate, 33% mucoid exudate, 5% purulent and 3% bloody fluid. Serous exudate was 59% in adult group, but serous (41%) and mucoid exudate (43%) was similar incidence in children. 5) In the preoperative tympanogram, there were 6% with type A, 91% with type B, and 3% with type C. The incidence of abnormal tympanogram (type B or C) was same in MEE patients of adenotonsillectomized children (95%) and the other children group (95%), and it was 93% in adult group. 6) Treatment by myringotomy and ventilation tube insertion resulted in postoperative improvement in air conduction hearing acuity especially in adenotonsillectomized children.