• Journal of Korean Neurosurgical Society
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• 제30권12호
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• pp.1439-1442
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• 2001

Solitary fibrous tumor(SFT) is a spindle cell neoplasm that usually arises in the pleura. Its involvement of the meninges is rare but increasingly being reported. Our case was a 33-year-old man who presented with clonic seizure around the right mouth angle and sensory disturbance at the right hand. Radiological studies showed a large extra-axial, dural-based mass in the left fronto-parietal region, typically isointense with gray matter and heterogeneous strong enhancement on T1-weighted images. Histologically, the tumor was composed of spindle-shaped cells growing in fascicles within the collagenous matrix. Immunohistochemical staining demonstrated diffuse CD34 positivity. Awareness of this neoplasm is necessary to accurate diagnosis.

• Tuberculosis and Respiratory Diseases
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• 제78권3호
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• pp.161-167
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• 2015

Tuberculosis (TB) remains a major global health problem, and the incidence of TB cases has not significantly decreased over the past decade in Korea. The standard short course regimen is highly effective against TB, but requires multiple TB-specific drugs and a long treatment duration. Recent studies using late-generation fluoroquinolones and/or high-dose rifapentine-containing regimens to shorten the duration of TB treatment showed negative results. Extending the treatment duration may be considered in patients with cavitation on the initial chest radiograph and positivity in sputum culture at 2 months of treatment for preventing TB relapse. Current evidence does not support the use of fixed-dose combinations compared to separate drugs for the purpose of improving treatment outcomes. All patients receiving TB treatment should be monitored regularly for response to therapy, facilitation of treatment completion, and management of adverse drug reactions. Mild adverse effects can be managed with symptomatic therapy and changing the timing of the drug administration, but severe adverse effects require a discontinuation of the offending drugs.

• Journal of Environmental Health Sciences
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• 제13권1호
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• pp.7-16
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• 1987

A study was carried out to determine the adequacy of springs as drinking water in summer and in winter separately. In this study, environmental sanitation, physio-chemical examination, bacteriologic contamination and the content of heavy metal were included. For this study, samples were collected from 8 springs which were located in the suburbs of Chunchon city. The following results were obtained. 1. There was the covering system in 1 out of 8 springs. 6 out of 8 springs showed contaminating source within lorn. 2. In physio-chemical test, six out of 8 springs were found to be unsafe for the legitimate standard of safty water. 3. Bateriologic examination clone during summer showed the evidence of coilform group at 7 out of 8 springs and during winter showed positivity at 3 out of 8 springs. 4. In the study for heavy metal content, all places showed high iron level beyond the standard level of salty water, and 4 places showed high contents of fluorine, mangan and lead.

• Journal of computational fluids engineering
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• 제18권2호
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• pp.41-48
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• 2013

Ice accretion on the solid surface is an importance factor in assessing the performance of aircraft and wind turbine blade. Changes in the external shape due to ice accretion can greatly deteriorate the aerodynamic performance. In this study, a three-dimensional upwind-type second-order positivity-preserving finite volume CFD scheme based on the unstructured mesh topology is developed to simulate two-phase flow in atmospheric icing condition. The code is then validated by comparing with NASA IRT experimental data on the sphere. The present results of the collection efficiency are found to be in close agreement with experimental data and show improvement near the stagnation region.

• Parasites, Hosts and Diseases
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• 제51권2호
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• pp.219-221
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• 2013

Reptiles, unlike mammals, have been considered to be unsuitable hosts of Trichinella spp., though larvae have been detected in their muscles and human outbreaks related to their consumption have, in fact, occurred. Herein we report 2 Korean cases of trichinosis, possibly transmitted via consumption of reptile meat. Both patients suffered from myalgia, headache, and facial edema. Laboratory examinations revealed leukocytosis with eosinophilia (54% and 39%, respectively) and elevated creatinine phosphokinase. ELISA was performed under the suspicion of trichinosis, showing positivity at the 29th and 60th day post-infection. Since they had consumed raw soft-shelled turtle meat, turtle was strongly suggested to be an infection source of trichinosis in Korea next to the wild boar and badger.

• Advances in aircraft and spacecraft science
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• 제5권5호
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• pp.551-579
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• 2018

This work is concerned with the motion of propeller driven airplanes, flying at constant velocity on ascending or descending rectilinear trajectories. Its purpose is to provide important features of rectilinear flights that are required for airplane trajectory planning but that cannot be found already published. It presents a method for calculating the amount of fuel used, the restrictions on the trajectory parameters, as inclination and speed, which result from the load factor, the lift coefficient, the positivity and upper boundedness of the power available. It presents a complete discussion of both ascending and descending flights, including gliding. Some original remarks are made about the parameters of gliding. It shows how to construct tables of parameters allowing to identify rapidly flyable trajectories. Sample calculations are shown for the Cessna 182 and a Silver Fox like unmanned aerial vehicle.

• Journal of applied mathematics & informatics
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• 제38권5_6호
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• pp.375-406
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• 2020

The anti-predator factor due to fear of predator in eco- epidemiological models has a great importance and cannot be evaded. The present paper consists of a modified Lesli-Gower predator-prey model with contagious disease in the predator population only and also consider the fear effect in the prey population. Boundedness and positivity have been studied to ensure the eco-epidemiological model is well-behaved. The existence and stability conditions of all possible equilibria of the model have been studied thoroughly. Considering the fear constant as bifurcating parameter, the conditions for the existence of limit cycle under which the system admits a Hopf bifurcation are investigated. The detailed study for direction of Hopf bifurcation have been derived with the use of both the normal form and the central manifold theory. We observe that the increasing fear constant, not only reduce the prey density, but also stabilize the system from unstable to stable focus by excluding the existence of periodic solutions.

• Journal of Korean Neurosurgical Society
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• 제39권2호
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• pp.152-155
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• 2006

Central neurocytoma is a rare, well-differentiated neuronal tumor and is usually located in the lateral or third ventricle of young adults. The occurrence of an intraventricular tumor with a characterisitic magnetic resonance image findings including isointense signal in T1-weighted images, the presence of a cystic component, small signal-void areas due to calcification, heterogenous and hyperintense "bubbly" appearance in T2-weighted images in a young patient should suggest preoperatively the diagnosis of central neurocytoma. The typical immunohistochemical finding, positivity for synaptophysin, is the main pathological feature. We experienced two cases of central neurocytomas with typical radiological and histopathological findings. We expect growth arrest of these cases by subtotal removal to avoid postoperative neurologic deficit followed by radiation therapy.

• Kyungpook Mathematical Journal
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• 제49권4호
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• pp.595-603
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• 2009

We show that for an algebraic Riccati equation $X^*B^{-1}X-T^*X-X^*T=C$, its solutions are given by X = W + BT for some solution W of $X^*B^{-1}X$ = $C+T^*BT$. To generalize this, we give an equivalent condition for $\(\array{B&W\\W*&A}\)\;{\geq}\;0$ for given positive operators B and A, by which it can be regarded as Riccati inequality $X^*B^{-1}X{\leq}A$. As an application, the harmonic mean B ! C is explicitly written even if B and C are noninvertible.

• Journal of Electrical Engineering and information Science
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• 제2권3호
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• pp.113-122
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• 1997

An adaptive input-output linearization technique for a robust speed control of a brushless C(BLDC) motor is presented. By using this technique, the nonlinear moro model can be effectively linearized in Brunovski canonical form, an the desired speed dynamics can be obtained based on the linearized model. This control technique, however, gives an undesirable output performance under the mismatch of the system parameters and load conditions caused by the incomplete linearization. for the robust output response, the controller parameters will be estimated by a model reference adaptive technique where the disturbance torque and flux linkage are estimated. The adaptation laws are derived by the Popov's hyperstability theory nd positivity concept. The proposed control scheme is implemented on a BLDC motor using the software of DSP TMS320C30 and the effectiveness is verified through the comparative simualtions and experiments.