• Childhood Kidney Diseases
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• v.11 no.1
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• pp.112-117
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• 2007

Although juvenile nephronophthisis(NPHP) is one of the most frequent genetic causes of chronic renal failure, it has very rarely been reported in Korean children. Most NPHP patients are found to have chronic renal failure, since there are no distinct clinical symptoms for NPHP except polydipsia, polyuria and enuresis in the early stage of disease. Ten percent of NPHP patients manifest retinitis pigmentosa, called $Senior-L\ddot{o}ken$ syndrome. We experienced 2 cases of $Senior-L\ddot{o}ken$ syndrome that occurred in siblings(a 10 year-old boy and a 14-year-old girl) who were diagnosed with Leber's amaurosis. They were found to have severe renal impairment without polydipsia and polyuria. However, no large homogenous deletion of the NPHPI(2q13) gene was not identified in these patients. We report here on these cases and we review the literature to emphasize the association between Leber's amaurosis and the development of chronic renal failure.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2004.08a
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• pp.207-215
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• 2004

There are various characteristics called for in work roll and intermediate rolls for cold rolling mills. Among these characteristics, the two main requirements are to ensure the quality of the rolled products and to reduce roll cost. To achieve these needs, resistance to wear, to thermal shock and to contact fatigue are especially important. This paper describes that new material(named DSR1) for intermediate rolls which greatly increases rolling campaign and improves resistance to wear has been developed. DSR1 was successfully manufactured and has been used in the cold rolling mill. It showed that Trial product was homogenous in hardness distribution and sufficient usable diameter. Also in service test, trial product is much more excellent rolling performance than conventional $5\%Cr$.

• Child Health Nursing Research
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• v.11 no.1
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• pp.125-131
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• 2005

Purpose: This study was done to evaluate the effects of massage on the level of stress hormone in the urine in preterm infants. Method: The design was a nonequivalent control group pretest-posttest design quasi experimental study. Fifty-eight preterm infants were assigned to the experimental(31) or control group(27). The data were collected from March 2002 to August 2003. The massage stimulation was provided to infants in the experimental group for 15-minutes twice a day for 10 days. On day 1 and day 10 of the study, a 24 hour-urine sample was collected for norepinephrine, epinephrine, and cortisol assays. In data analysis, SPSSWIN 10.0 program was utilized for descriptive statistics, ANOVA and t-test. Results: General characteristics of the two groups showed no significant differences, thus the two groups were found to be homogenous. The 24 hour-urine cortisol of the massage group (t=4.61, p=.000) was significantly reduced compared to the control group after 10 days. Conclusions: The results suggest that the massage stimulation can be used to reduce 24 hour-urine cortisol in preterm infants. Therefore, massage provided in the incubator is recommended for reduction of stress in preterm infants who are hospitalized in neonatal intensive care units.

• Smart Structures and Systems
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• v.14 no.1
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• pp.55-70
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• 2014

The paper presents a multi-objective optimization strategy for a multi-type sensor placement for Structural Health Monitoring (SHM) of long span bridges. The problem is formulated for simultaneous placement of strain sensors and accelerometers (heterogeneous network) based on application demands for SHM system. Modal Identification (MI) and Accurate Mode Shape Expansion (AMSE) were chosen as the application demands for SHM. The optimization problem is solved through the use of integer Genetic Algorithm (GA) to maximize a common metric to ensure adequate MI and AMSE. The performance of the joint optimization problem solved by GA is compared with other established methods for homogenous sensor placement. The results indicate that the use of a multi-type sensor system can improve the quality of SHM. It has also been demonstrated that use of GA improves the overall quality of the sensor placement compared to other methods for optimization of sensor placement.

• Journal of Yeungnam Medical Science
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• v.8 no.2
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• pp.217-221
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• 1991

The fibromatosis is a rare tumorous with local invasion, but is not metastasized distantly. This term should not be applied to nonspecific reactive fibrous proliferations that are part of an inflammatory process of are secondary to injury of hemorrhage and have no tendency toward growth or recurrence. It arises principally from the connnective tissue of muscle and overlying fascia or aponeurosis(musculaponeurotic fibromatosis), and chiefly affects the muscle of shoulder, pelvic girdle, and extremity. The term 'aggressive fibromatosis' is also employed to describe this disease, but it is impossible to predict the clinical course in the individual case. The fibromatosis arising in the mediastinum is very rare, and the report about it is nearly absent. The plain radiography shows merely mass with soft tissue density. The CT demonstrates a poorly defined homogenous or heterogenous mass, isodense with skeletal muscle on precontrast-images, and slightly hyperdense to muscle on postcontrast-scan. Accurate delineation between the tumor & surrounding tissue is vague or frequently impossible. The authors experienced one case of the mediastinal fibromatosis recently and report the case with review of concerned literature.

• Advances in materials Research
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• v.5 no.3
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• pp.131-140
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• 2016

Copper/silicon nitride ($Cu/Si_3N_4$) composites are fabricated by powder technology process. Copper is used as metal matrix and very fine $Si_3N_4$ particles (less than 1 micron) as reinforcement material. The investigated powder were used to prepare homogenous ($Cu/Si_3N_4$) composite mixtures with different $Si_3N_4$ weight percentage (2, 4, 6, 8 and10). The produced mixtures were cold pressed and sintered at different temperatures (850, 950, 1000, $1050^{\circ}C$). The microstructure and the chemical composition of the produced $Cu/Si_3N_4$ composites were investigated by (SEM) and XRD. It was observed that the $Si_3N_4$ particles were homogeneously distributed in the Cu matrix. The density, electrical conductivity and coefficient of thermal expansion of the produced $Cu/Si_3N_4$ composites were measured. The relative green density, sintered density, electrical conductivity as well as coefficient of thermal expansion were decreased by increasing the reinforcement phase ($Si_3N_4$) content in the copper matrix. It is also founded that the sintered density and electrical conductivity of the $Cu/Si_3N_4$ composites were increased by increase the sintering temperature.

• Advances in Computational Design
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• v.3 no.3
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• pp.213-232
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• 2018

First time, an exact solution for free vibration of the Levy-type rectangular laminated plate is developed considering the most efficient Zig-Zag theory (ZIGT) and third order theory (TOT). The plate is subjected to hard simply supported boundary condition (Levy-type) along x axis. Using the equilibrium equations and the plate constitutive relations, a set of 12 m first order differential homogenous equations are obtained, containing displacements and stress resultant as primary variables. The natural frequencies of a single-layer isotropic, multi-layer composites and sandwich plates are tabulated for three values of length-to-thickness ratio (S) and five set of boundary conditions and further assessed by comparing with existing literature and recently developed 3D EKM (extended Kantorovich method) solution. It is found that for the symmetric composite plate, TOT produces better results than ZIGT. For antisymmetric and sandwich plates, ZIGT predicts the frequency for different boundary conditions within 3% error with respect to 3D elasticity solution while TOT gives 10% error. But, ZIGT gives better predictions than the TOT concerning the displacement and stress variables.

• Earthquakes and Structures
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• v.14 no.2
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• pp.179-186
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• 2018

We present the accurate investigation the seismic behavior of the gravity retaining wall built near rock face based on numerical method. The retaining wall is a useful structure in geotechnical engineering, where the earthquake is a common phenomenon; therefore, the evaluation of the behavior of the retaining wall during an earthquake is essential. However, in all previous studies, the backfill behind the wall was usually approximated by a homogeneous region, while in contrast, in practice, in many cases retaining walls are used to support the soil pressure in, inhomogeneous, mountainous area. This suggests an accurate investigation of the problem, i.e., numerical analysis. The numerical results will be compared with some of recently proposed analytical methods to show the accuracy of the proposed method. We show that increasing the volume of the rock face yields decreasing the permanent horizontal displacement of the gravity retaining wall built near rock face. Besides, we see that the permanent horizontal displacement of the gravity retaining wall with homogenous backfill is more than permanent horizontal displacement of the gravity retaining wall case of the built near rock face in different frequency contents.

• Bulletin of the Korean Mathematical Society
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• v.51 no.5
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• pp.1241-1257
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• 2014

We consider a class of hypoelliptic operators of the following type $$L=\sum_{i,j=1}^{p_0}a_{ij}{\partial}^2_{x_ix_j}+\sum_{i,j=1}^{N}b_{ij}x_i{\partial}_{x_j}-{\partial}_t$$, where ($a_{ij}$), ($b_{ij}$) are constant matrices and ($a_{ij}$) is symmetric positive definite on $\mathbb{R}^{p_0}$ ($p_0{\leqslant}N$). By establishing global Morrey estimates of singular integral on the homogenous space and the relation between Morrey space and weak Morrey space, we obtain the global weak Morrey estimates of the operator L on the whole space $\mathbb{R}^{N+1}$.

• Journal of Korean Neurosurgical Society
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• v.60 no.3
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• pp.380-384
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• 2017

Glioblastoma multiforme (GBM) is located most frequently in the cerebral hemispheres. Glioblastoma presenting as an extraaxial mass of cerebellopontine angle (CPA) is very rare in adults. We report a rare case of GBM arising in the CPA. The patient was a 71-year-old female, who complained of progressive gait disturbance and poor memory. Initial magnetic resonance imaging (MRI) revealed a $1.4{\times}1.3cm$ mass in the left CPA, with broad base to the petrous bone, showing homogenous enhancement. Follow-up MRI showed a rapid increase in size of mass ($2.7{\times}2.2cm$) with a necrotic portion. A stereotactic biopsy was done under the guidance of navigation system, and the histopathologic diagnosis was GBM, World Heath Organization grade IV. Further surgical resection was not performed considering her general condition, and the patient underwent concurrent chemotherapy with radiation therapy. Although rare, the possibility of glioblastoma should be included in the differential diagnosis of atypical CPA tumor.