• Journal of Ocean Engineering and Technology
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• v.2 no.1
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• pp.170-175
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• 1988

A study on the dynamic vibration absorber with coil spring and oil damper was carried out both theoretically and experimentally. A main mass is attached to a foundation using coil spring and oil damper. A harmonic motion was applied to the foundation. The effects of the dynamic vibration sbsorber are theoretically summarized in graphs, and tested on a vibratory model for the isolation of actual mechanical vibration. As a result, the first resonance amplitude ratio increased and the second resonance amplitude ratio decreased as the absorber spring constant increased. When the absorber mass increase, the first resonance amplitude ratio is decreased and the second resonace amplitude ratio is increased.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2011.04a
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• pp.627-632
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• 2011

This study was carried out vibration attenuation of vibration absorber attached to the cantilever beam structure. Modern tank guns are stabilized to allow fire on the move while traversing uneven terrain. However, as the length of the barrel is extended, to meet required muzzle exit velocities, the terrain induced vibrations lead to increased muzzle pointing errors. Thus, reducing these vibrations should lead to increased accuracy. The vibration absorber includes a compliant energy storage device, such as a spring, and a mass secured to the energy storage device. In this study, it accomplished a research in about gun barrel vibration attenuation using tuned mass damper. The barrel was hung from a bungee cord for free - free condition. It accomplished a vibration experiment for verified attenuation efficiency.

• Journal of Chest Surgery
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• v.48 no.1
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• pp.95-97
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• 2015

We report the case of a 69-year-old woman who was diagnosed with intracardiac schwannoma without symptoms. Preoperative echocardiography and cardiac magnetic resonance imaging showed a mass attached to the interatrial septum. The initial diagnosis was a myxoma or a bronchogenic cyst. The tumor was successfully excised under cardiopulmonary bypass. However, the pathology of the excised tumor was consistent with schwannoma. We suggest that cardiovascular surgeons consider schwannoma to be a possible differential diagnosis for a mass close to the interatrial septum.

• Korean Journal of Veterinary Service
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• v.20 no.2
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• pp.183-189
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• 1997

This article reports a spontaneous thoracic teratoma in a laying hen (Deklb brown warren). In this case, a 40 days old hen was submitted for necropsy as part of an investigation into a flock problem suspected Marek's disease to Chonbuk Veterinary Service Laboratory in 1983. On the gross finding, mass was In the cranial subpulmonary cavity and attached to the vertebral column. It contained fully developed contour feathers. Histologically, feathers were arised from feather follicles complete with arrector plumi muscle, nerve, vessel and mucous gland composed with simple tall columnar epithelium. The outer surface of mass was lined by keratinized or nonkeratinized stratified squamous epithelium. It converted to pseudostratified ciliated columnar epithelium in some area. There were lymphocyte infiltration around gland tissue and eosinophilic intranuclear inclusion bodies in nonkeratinized epithelium. This thoracic teratoma was composed of ectodermal origin, squamous epithelium and nerve, and endodermal origin, mucous gland. This case in laying hen has never been reported in the literature in the world.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.15 no.2 s.95
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• pp.161-168
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• 2005

The absorbing material is mostly used to changing the acoustic energy to the heat energy in the passive control, and that consists of the porous media. That controls an air borne noise while the stiffened plates, damping material and additional mass control a structure borne noise. The additional mass can decrease the sound by mass effect and shift of natural frequency, and damping material can decrease the sound by damping effect. The passive acoustic control using these kinds of control materials has an advantage that is possible to control the acoustic in the wide frequency band and the whole space at a price as compared with the active control using the various electronic circuit and actuator. But the space efficiency decreased and the control ability isn't up to the active control. So it is necessary to maximize the control ability in the specific frequency to raise the capacity of passive control minimizing the diminution of space efficiency such an active control. Therefore, the characteristics of control materials and the optimum layout of control materials that attached to the boundary of structure-acoustic coupled cavity were studied using sequential optimization on this study.

• Journal of Preventive Medicine and Public Health
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• v.50 no.4
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• pp.262-267
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• 2017

Objectives: The US ranks ninth in obesity in the world, and approximately 7% of US adults experience major depressive disorder. Social isolation due to the stigma attached to obesity might trigger depression. Methods: This paper examined the impact of obesity on depression. To overcome the endogeneity problem, we constructed pseudopanel data using the Behavioral Risk Factor Surveillance System from 1997 to 2008. Results: The results were robust, and body mass index (BMI) was found to have a positive effect on depression days and the percentage of depressed individuals in the population. Conclusions: We attempted to overcome the endogeneity problem by using a pseudo-panel approach and found that increases in the BMI increased depression days (or being depressed) to a statistically significant extent, with a large effect size.

• Journal of Chest Surgery
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• v.33 no.2
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• pp.203-206
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• 2000

A 44-year-old man was transferred to our department for mediastinal mass. He had suffered from only an easily fatiguable condition for 1 month. A physical examination and laboratory finding of the patient disclosed no abnormality. A chest radiograph showed a soft tissue tumor in the posterior mediastinum. It was well circumscribed and ovoid. Invasions to adjacent organs were not seen. Therefore it was though the 5th intercostal space. The tumor mass was attached to the visceral pleura of the right upper lobe by a pedicle and this pedunculated tumor laid entirely within the pleural cavity. Excision of the tumor which measured 7$\times$7$\times$3cm was done easily. Pathologic studies confirmed the diagnosis of localized fibrous tumor of the pleura. Localized fibrous tumor of the pleura is rare, This tumor along ith the evidence from ultrastructural and immunohistochemical studies has led most researchers to conclude that localized fibrous tumor is not of the mesothelial origin but arises in the submesothelial connective tissue.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.28 no.8 s.227
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• pp.910-920
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• 2004

The heat/mass transfer characteristics in a rotating two-pass duct with and without rib turbulators are investigated in the present study. The square duct has a hydraulic diameter ($D_h$) of 26.7 mm, and $1.5\;mm{\times}1.5\;mm$ square $90^{\circ}$-rib turbulators are attached on the leading and trailing walls. The pitch-to-rib height ratio (p/e) is 10. The Reynolds number based on the hydraulic diameter is kept constant at 10,000 to exclude the Reynolds effect, and the rotation number is varied from 0.0 to 0.20. In the smooth duct, the curvature of the $180^{\circ}$-turn produces Dean vortices that enhance heat/mass transfer in the post-turn region. When rib turbulators are installed, heat/mass transfer is augmented 2.5 times higher than that of the smooth duct since the main flow is turbulated by reattaching and separating in the vicinity of the duct surfaces. The duct rotation results in heat/mass transfer discrepancy so that Sherwood number ratios are higher on the trailing surface in the first-pass and on the leading surface in the second-pass. In the turning region, Dean vortices shown in the stationary case transform into one large asymmetric vortex cell, and subsequent heat/mass transfer characteristics also change. As the rotation number increases, the heat/mass transfer discrepancy enlarges.

• Journal of Korean Neurosurgical Society
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• v.39 no.2
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• pp.156-158
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• 2006

We present a case of olfactory schwannoma in a 16-year-old boy with headache and diplopia. Brain computed tomography[CT] scan and magnetic resonance[MR] imaging showed a huge mass in the subfrontal area resembling an olfactory groove meningioma. We performed a bifrontal craniotomy and found out the mass was attached to cribriform plate but was not related to the olfactory tract or bulb. The histopathological diagnosis of schwannoma was confirmed by immunohistochemical staining for S-100, vimentin and others. We describe the clinical manifestations, radiological characteristics, histological aspects, and differential diagnosis of this tumor with literature review.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.24 no.2
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• pp.469-475
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• 1994

The benign cementoblastoma is a benign odontogenic tumor of cemental-forming tissue, which has an unlimited growth potential. The radiographic appearance of the lesion is pathognomonic and consists of a radiopaque mass surrounded by a thin radiolucent line. This mass is inseparable, radiologically, from the tooth root and is attached to it. Microscopic evaluation suggests that the lesion enlarges by peripheral growth, with the center of the neoplasm being more calcified and inactive than the periphery. We have observed two cases of beneign cementoblastoma{mature calcified stage) occured in the left mandibular first molar of 22-year-old man and 14-year-old man.