• The KSFM Journal of Fluid Machinery
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• v.8 no.3 s.30
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• pp.7-15
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• 2005

A Navier-Stokes code has been developed to simulate the flow through a cross flow fan. It is based on an unstructured finite volume method and uses moving grid technique to model the rotation of the fan. A low Reynolds number turbulence model is used to calculate eddy viscosity. The basic algorithm is SIMPLE. Numerical simulations over a wide range of flow rate aye carried out to validate the code. Comparison of all numerical solutions with experimental data confirms the validity of the present code. Present numerical solutions show a noticeable improvement over a previous numerical method which is based on a model of body force to simulate the rotation of the impeller.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.60 no.4
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• pp.206-213
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• 2011

Line sleeves, which used to connect ACSR cables when transmission lines were constructing, sometimes cause power transmission failure due to deterioration and corrosion. Therefore, power transmission line should be inspected regularly to prevent national disaster. Current inspection tool detects insertion length of transmission line on line sleeves, the inspection tool includes enormous error by operator. Moreover, the system is not controlled remotely, negligent accident would be caused while inspecting. To deal with those problems, KEPCO reviewed several ways to inspect line sleeves and proposes new method to inspect line sleeve by measuring magnetic flex which penetrate junction of steel and aluminum sleeve. The developed inspection tool is reliable enough to detect eccentric sleeves. Also, the developed inspection device was applied on actual transmission line and verified its effectiveness.

• Journal of Korean Neurosurgical Society
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• v.38 no.5
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• pp.387-389
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• 2005

Primary atypical teratoid/rhabdoid tumor[AT/RT] of the central nervous system is a recently described, highly malignant neoplasm that usually occur in the posterior fossa of children. Although AT/RT usually occurs in young children, AT/RT is being recognized in adults with increasing frequency. The authors report 49-year-old man with multiple AT/RT lesions [right lateral ventricle, right temporal lobe and right cerebellum]. Histopathologic findings showed typical rhabdoid cells with eccentric nuclei and prominent nucleoli. Eventhough the tumor was removed, a patient was dead in one month after surgery due to recurrence and rapid regrowth of the tumor.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.24 no.12
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• pp.156-163
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• 2010

The brushless motor is getting widely applied to the automotive component with the advantage of the high efficiency, high reliability and etc.. Most of the motor applications require the low vibration and acoustic noise. The cogging torque is the one of the main cause of the noise and vibration. The step-skewed rotor is used to reduce the cogging torque. We analyze the characteristics of the step-skewed rotor and non skewed rotor with the same stator by using 2-dimensional FEM. And then we analyze the characteristics variation according to the rotor eccentricity. The prototype is made and tested. As the results, the step-skewed rotor structure reduce the cogging torque and local radial force but it is more sensitive to rotor eccentricity.

• Composites Research
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• v.15 no.4
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• pp.37-42
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• 2002

We consider the problem of determining the singular stresses and electric fields in a functionally graded piezoelectric ceramic strip containing a Griffith eccentric crack under anti-plane shear loading with the theory of linear piezoelectricity. Fourier transforms are used to reduce the problem to the solution of two pairs of dual integral equations, which are then expressed to a Fredholm integral equation of the second kind. Numerical values on the stress intensity factor and the energy release rate are obtained.

• Transactions of the Korean Society of Mechanical Engineers
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• v.19 no.1
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• pp.1-13
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• 1995

In order to investigate the effect of liquid balancer in washing machine, we identify the vibration characteristics of suspension system of washing machine and formulate the 4 D. O. F. system dynamic equations. As the washing machine rotates higher speed, it is emphasized to reduce the ecentric force due to unbalanced mass. Nowadays, the most effective cancelling method of eccentric force is known as the usage of liquid balancer. To determine the liquid distribution in liquid balancer, the fluid statics is considered. The system dynamic equations are solved by Runge-Kutta method and represent the good characteristics of real washing machine in X-Y plane. The accuracy of the numerical solution was examined by experiments. The simulation results show that the unbalanced mass has so much influence on vibration magnitude and the rotating shape of spin-basket. But the effect of mass reduction due to the dehydration of the spin-basket has little influence on transient vibration.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.11b
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• pp.182-186
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• 2002

If a sinusoidal excitation force moves back and forth along a structure with a certain frequency, the structure will be excited with the difference frequency of these two frequencies. A low frequency vibration shaker has been developed using this force frequency shifting without actually moving a shaker. The shaker consists of an ordinary eccentric mass shaker, a plate, constant springs, and time varying dampers. The dampers are turned on and off in a sequential manner to simulate a traveling slide of an excitation force. The operation of the shaker is simulated by solving the equations of motion of the shaker. Characteristics of the shaker have been found and they will be utilized to design efficient low frequency shakers.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.11b
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• pp.1054-1059
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• 2002

A linearly tapered beam immersed partially in other material is considered and is modelled as a linearly tapered Bernoulli-Euler beam fixed at the bottom with a concentrated mass at the top. Its governing equations is derived and its free vibration analysis is performed for various boundary conditions. And the rotatory inertia of the eccentric lumped tip mass is considered. The problem of determining the natural frequencies leads to an eighth order determinant. The solutions of the frequency equations are obtained numerically. The non-dimensional frequency parameters are given in tabular form and the influence of non-dimensional parameters on natural frequency is discussed for various conditions.

• The Korean Journal of Cytopathology
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• v.8 no.2
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• pp.170-173
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• 1997

Langerhans' cell histiocytosis is a relatively rare disorder of children, characterized by abnormal proliferation of Langerhans' cells. It usually presents as multiple osteolytic lesion with lymphadenopathy or cutaneous manifestations. We experienced a case of Langerhans' cell histiocytosis involving bone and lymph node, diagnosed by fine needle aspiration cytology of the lymph node. The patient was a 10-year old girl with left inguinal lymphadenopathy. Fine needle aspiration cytology from the lymph node disclosed very cellular smear consisted of Langerhans' cells, eosinophils and lymphocytes. The Langerhans' cells had eccentric oval to reniform shape nuclei with grooving and abundant pale cytoplasm. The diagnosis was confirmed later by histologic study of bone lesion.

• Journal of Korean Physical Therapy Science
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• v.8 no.2
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• pp.1065-1071
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• 2001

Delayed onset muscle soreness is a sensation of discomfort that occurs 24 h after exercise, and it is associated with the performance of unfamiliar and high force muscle work, such as eccentric contractions. The injury to the muscle has been well described but the mechanism underlying the injury is not fully understood. Although the pathophysiological processes underlying delayed onset muscle soreness are not completely understood, many researchers have investigated various treatments in a attempt to reduce the soreness. Physical therapy is the most importance techniques to reduce delayed onset muscle soreness. The purpose of this study is to investigate the effect of a cryotherapt on DOMS. Thirty subjects were randomly assigned to experimental group : control, cryotherapy, and placebo group. Elbow flexion range, mechanical pain threshold. and subjective pain were measured 30 min before DOMS was induced and 24, 48, 72 hours after DOMS was induced. The results of this study were as follows: 1. Elbow flexion range showed significant difference each time, especially at 48 and 72 hours 2. Mechanical pain thershold and subjectively pain showed no significant difference between group.