• Smart Structures and Systems
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• 제9권5호
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• pp.427-439
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• 2012

The present paper deals with the analytical solution of a functionally graded piezoelectric (FGP) cylinder in the magnetic field under mechanical, thermal and electrical loads. All mechanical, thermal and electrical properties except Poisson ratio can be varied continuously and gradually along the thickness direction of the cylinder based on a power function. The cylinder is assumed to be axisymmetric. Steady state heat transfer equation is solved by considering the appropriate boundary conditions. Using Maxwell electro dynamic equation and assumed magnetic field along the axis of the cylinder, Lorentz's force due to magnetic field is evaluated for non homogenous state. This force can be employed as a body force in the equilibrium equation. Equilibrium and Maxwell equations are two fundamental equations for analysis of the problem. Comprehensive solution of Maxwell equation is considered in the present paper for general states of non homogeneity. Solution of governing equations may be obtained using solution of the characteristic equation of the system. Achieved results indicate that with increasing the non homogenous index, different mechanical and electrical components present different behaviors along the thickness direction. FGP can control the distribution of the mechanical and electrical components in various structures with good precision. For intelligent properties of functionally graded piezoelectric materials, these materials can be used as an actuator, sensor or a component of piezo motor in electromechanical systems.

• Nuclear Engineering and Technology
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• 제51권5호
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• pp.1241-1250
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• 2019

This study mainly focused on the neutronics modeling of bubbles in bubbly flow in boiling water reactors. The bubble, ring and homogenous models were used for radial void fraction distribution. Effect of the bubble and ring models on the infinite multiplication factor and two-group flux distribution was investigated by comparing with the homogenous model. Square pitch unit cell geometry was used in the calculations. In the bubble model, spherical and non-spherical bubbles at random positions, sizes and shapes were produced by Monte Carlo method. The results show that there are significant differences among the proposed models from the viewpoint of physical interaction mechanism. For the fully-developed bubbly flow, $k_{inf}$ is overestimated in the ring model by about $720{\pm}6pcm$ with respect to homogeneous model whereas underestimated in the bubble model by about $-65{\pm}9pcm$ with a standard deviation of 15 pcm. In addition, the ring model shows that the coolant must be separated into regions to properly represent the radial void distribution. Deviations in flux distributions principally occur in certain regions, such as corners. As a result, the bubble model in modeling the void fraction can be used in nuclear engineering calculations.

• Journal of the Optical Society of Korea
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• 제17권2호
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• pp.130-135
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• 2013

Based on the extended Huygens-Fresnel principle and generalized Stokes theory, the evolution of polarization properties of beams generated by quasi-homogenous (QH) sources propagating in clear oceanic water was studied by the use of the oceanic turbulence spatial spectrum function. The results show that the beams have similar polarization self-reconstructed behavior under different turbulence conditions in the far field, but if the propagation distance is not long enough, the degree of polarization (DOP) fluctuates with much more complexity than state of polarization (SOP) of QH beams. The self-reconstructed ability of DOP at the special distance in turbulence would get to the best value if the values of coherence of width were chosen suitably, but for SOP, it has no best value.

• Imaging Science in Dentistry
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• 제31권3호
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• pp.175-179
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• 2001

Cystic lymphangioma is an uncommon benign developmental tumor of the lymphatic system, seen rarely in adults. A 23-year-old man visited DKUDH complaining of the painless swelling in the right submandibular area. It was reported that swelling had increased since 5 months ago. Clinically, fltriangle uctuant and mobile mass was palpated at the right submandibular area. CT scan showed a large, well-defined, homogenous low density mass, measuring 5.0 × 2.5 × 4.0 cm. T1W MRI scan demonstrated a large, multiseptated homogenous low signal mass with septum and rim enhancement. Proton-density and T2W MRI scan showed mass of high signal intensity. MRI scan was able to delineate better the enhanced multi septation and extent of the lesion. Histopathologically, a lobulated cystic mass lined by a layer of flattened endothelium was observed.

• Smart Structures and Systems
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• 제4권2호
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• pp.171-182
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• 2008

In this paper, a methodology for the estimation of masonry elasticity and shear moduli is presented, for linear elasticity considerations. The methodology is based on the assumption that for a "periodic" masonry wall, which is formed by the repetition of a basic unit containing blocks and mortar, the mechanical characteristics of the unit are representative of the characteristics of the entire wall. For their calculation, the finite element analysis method is used. A micro-model with finite elements simulating separately the blocks and the mortar is developed. An equivalent finite element model, using an homogenous material is also developed and assuming equivalence of strains for the two models, the homogenous material properties are estimated. The efficiency of the method and its applicability limits are investigated.

• Journal of Contemporary Eastern Asia
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• 제13권2호
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• pp.57-68
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• 2014

How do party organizations respond to newly evolving social groups? Research on Indian party organizations reveals that in multiethnic societies with uneven modernization between social groups, internally competitive parties respond better to newly evolving groups. Moreover, it is claimed: the same dynamic works vis-$\grave{a}$-vis homogenous societies with cleavages based on economic differences; and, the pattern holds regardless of differences in electoral institutions. This study examines these claims by testing whether factional competition correlated with recruitment into Japan's Liberal Democratic Party in 1972 and 1983. Japan had a single-nontransferable-vote system with multi-member districts, while the research on India assumes a first-past-the-post system with single-member districts. This study conducts a difference of means test on the population of new and old politicians in the LDP in 1972 and 1983 with a pooled variance adjustment to account for differences in populations' size. The findings show that intra-party competition and recruitment are not correlated in Japan, thus tentatively rejecting both claims.

• 산업경영시스템학회지
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• 제5권6호
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• pp.69-78
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• 1982

Traditional CVP (Cost-Volume-Profit) analysis employs linear cost and revenue functions within some specified time period and range of operations. Therefore CVP analysis is assumption of constant labor productivity. The use of linear cost functions implicity assumes, among other things, that firm's labor force is either a homogenous group or a collection homogenous subgroups in a constant mix, and that total production changes in a linear fashion through appropriate increase or decrease of seemingly interchangeable labor unit. But productivity rates in many firms are known to change with additional manufacturing experience in employee skill. Learning curve is intended to subsume the effects of all these resources of productivity. This learning phenomenon is quantifiable in the form of a learning curve, or manufacturing progress function. The purpose d this study is to show how alternative assumptions regarding a firm's labor force may be utilize by integrating conventional CVP analysis with learning curve theory, Explicit consideration of the effect of learning should substantially enrich CVP analysis and improve its use as a tool for planning and control of industry.

• Journal of Chest Surgery
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• 제33권1호
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• pp.7-19
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• 2000

Background :To assess the accuracy of Electron-Beam Tomography(EBT) in following evaluation of the pulmonary vascular system after a shunt operation in the cyanotic con-genital heart disease with pulmonary stenosis or pulmonary atresia. Material and Method : Sixteen patients(M:F=11:5) who received Blalock-Taussig(n=8) bidirectional cavo-pulmonary shunt(n=10) and unifocalization (n=2) were ncluded in the study. We evaluated the patency of the shunt the morphology of intrapericardial and hilar pulmonary arteries(PA) peripheral pulmonary vascularity by background lung attenuation and the abundance of arterial & venous collateral. Angiography(n=12) and echocardiography(n=20) were used as the gold standard for the comparison of EBT results. Result: EBT was consistent with angiogram/ echo in 100% of the evaluation for the patency of the shunt and in 12(by angiogram 100%) and 19(by echo 95%) for the detection the hypoplasia stenosis or interruption of central PA In measuring of PA EBT and angiogram corrlated(r=0.91) better than EBT-echo(r=0.88) or echo-angiogram(r=0.72) Abundant systemic arterial collateral were noted in 4 and venous collateral in 3 cases. In evaluating the peripheral pulmonary vascularity the homogenous and normal-ranged lung attenuation(m=6) decreased but homo-genous attenuation(n=1) segment-by-sgment heterogeneous attenuation(n=3) homogenous but asymmetrical attenuation(n=3) segment-by-segment heterogeneous attenuation(n=3) homogenous but asymmetrical attenuation(n=3) and venous congestion(n=2) were observed nd 12 of them were compatible with the blood flow pattern revealed by cardiac catheterization. Conclusion: EBT was accurate in the integrated evaluation of the pulmonary vascular system after the shunt including the patency of the shunt operaion the morphology and dimension of the central and hilar PAs and the loco-regional pulmonary flow in the lung parenchyma. It suggests the useful information about the need of secondary shunt operation the proper timing time for total repair and the need of interventional procedure prior to total repair.

• Journal of Yeungnam Medical Science
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• 제10권1호
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• pp.58-67
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• 1993

1986년 5월부터 1991년 6월까지 약 5년간 영남대학교 외과대학 부속병원에 내원하여 혈액학적 소견상 빈혈이 동반된 환자 210명과 정상인 200명 도합 410명을 대상으로 Coulter Counter S-plus II로 일반혈액검사를 실시하여 MCV와 RDW 및 여러 적혈구 지수를 얻어서 빈혈의 새로운 분류를 시도하였고 외국인에 비하여 빈혈의 병인 양상이 다른 한국인의 혈액질환의 감별진단에 도움이 되는 가를 알아 보고자 본 연구를 시행하였다. 거의 모든 경우에 MCV의 증감은 MCH와 MCHC의 증감을 동반하였으나 RDW와는 무관하였다. 따라서 저색소성빈혈 혹은 정색소성빈혈등의 용어보다는 이질성빈혈 혹은 동질성빈혈의 용어를 사용함이 빈혈의 형태학적 분류에 더욱 의미있는 것으로 사료되었다. 이질성소구성빈혈에는 철결핍성빈혈이 속하였고 이질성정구성빈혈에는 급성백혈병과 골수로성빈혈이 여기에 속하였으며 이질성대구성빈혈에는 거대적아구성빈혈과 용혈성빈혈이 속하였다. 동질성소구성빈혈에는 만성질환에 의한 빈혈이 여기에 속하였으며 동질성정구성빈혈에는 급성출혈, 만성백혈병 및 다발성 골수종등에 의한 빈혈이 여기에 속하고 동질성대구성빈혈에는 재생활량성빈혈이 여기에 속하였다. 진단적인 의의가 큰 혈색소병은 본 연구에는 관찰되지 않았지만 한국인에 가장 많은 빈혈의 원인인 철결핍성빈혈과 만성질환에 의한 빈혈의 감별진단에 RDW가 유용한 것으로 생각되었다.

• 대한수학회논문집
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• 제11권4호
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• pp.1061-1066
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• 1996

We will give an example which is a normal Hausdorff countable dense homogeneous space but not a densely homogeneous space. Next, we will give a proof for the fact that every nondegenerate component of densely homogenous spaces is open and densely homogeneous.