• Earthquakes and Structures
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• v.4 no.2
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• pp.133-155
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• 2013

The earthquake responses are studied for the tall flexible structures such as TV towers when the vertical eccentricities between the discrete nodes and the corresponding centroids of investigated lumps are considered. In practical analyses, the tall flexible structures can be made into a spatial-discrete system of some certain length of beam elements with different lengths and cross-sectional areas. These elements are used to construct the investigated lumps in this paper. The different cross-sectional areas and the different lengths of two adjacent elements lead to the appearance of vertical eccentricity between the discrete node and the centroid of investigated lump within the same investigated lump. Firstly, the governing equations are established for a typical investigated lump. Secondly, the calculating formulae of the forces and moments acting on the investigated lump are derived and provided. Finally the new dynamic equilibrium equations with modified mass matrix and assemblage of stiffness matrix have been derived for the stick MDOF model based on beam theory when the existing vertical eccentricities are considered. Numerical results demonstrate that these vertical eccentricities should be considered in order to obtain the accurate earthquake responses for the tall flexible structures.

• Steel and Composite Structures
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• v.3 no.3
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• pp.213-229
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• 2003

A high precision shear deformable triangular element has been proposed for free vibration analysis of composite trapezoidal plates. The element has twelve nodes at the three sides and four nodes inside the element. Initially the element has fifty-five degrees of freedom, which has been reduced to forty-eight by eliminating the degrees of freedom of the internal nodes through static condensation. Plates having different side ratios (b/a), boundary conditions, thickness ratios (h/a=0.01, 0.1 and 0.2), number of layers and fibre angle orientations have been analyzed by the proposed shear locking free element. Trapezoidal laminate with concentrated mass at the centre has also been analyzed. An efficient mass lumping scheme has been recommended, where the effect of rotary inertia has been included. For validation of the present element and formulation few results of isotropic trapezoidal plate and square composite laminate have been compared with those obtained from open literatures. The numerical results for composite trapezoidal laminate have been given as new results.

• Korean Journal of Head & Neck Oncology
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• v.32 no.1
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• pp.49-52
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• 2016

The lobular capillary hemangioma (LCH) was previously known to pyogenic granuloma and is benign vascular lesion which grows rapidly on skin and mucosa. It arises from whole body, but oral and nasal cavities are most predilection sites in the head and neck area. The laryngeal LCH looks like a granulomatous lesion of posterior glottis and its common etiology are tracheal intubation and laryngopharyngeal reflux disease etc. The LCH in larynx can cause blood tinged sputum and lump sense. The lesions refractory to medical therapy or causing dyspnea may require surgical excision. A 74-year-old man who presented gradually aggravated dyspnea, lump sensation and hoarseness of one month came to our hospital. The stroboscopic examination revealed large well-margined glottic mass. It was excised with $CO_2$ laser and finally diagnosed as LCH. We present a rare unique case of glottic LCH with a review of literatures.

• Korean Journal of Head & Neck Oncology
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• v.31 no.1
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• pp.31-33
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• 2015

The extranodal non-Hodgkin lymphoma is uncommonly occurred in larynx, accounting for less than 1% of all laryngeal neoplasm. In general, the laryngeal lymphoma is appeared as submucosal mass without mucosal ulceration and is most commonly found in supraglottis. The primary laryngeal lymphoma constitute a diagnostic challenge because they are characterized by absence of clinical and gross differential criteria, compared with squamous cell carcinoma (SCC). We encountered a 74-year-old man with hoarseness and lump sensation in the throat. On direct laryngoscope, multiple ulcerative and exudative mass in glottis and supraglottic areas were observed. The patient was finally diagnosed as large B-cell lymphoma through the laryngeal microsurgery. He received radiation therapy and there is no evidence of recurrence. Although the laryngeal mass has superficial mucosal change, primary laryngeal lymphoma must be included in the differential diagnosis.

• Applied Microscopy
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• v.52
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• pp.3.1-3.8
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• 2022

Our purpose in this study is to analyze the microstructural characteristics and constituent elements of inorganic substances added to the yellow ink and red ink pigments used in permanent makeup. We observed the microstructural properties of inorganic pigments added to the ink using a scanning electron microscopy (SEM) and analyzed the constituent elements of the inorganic pigment particles using an energy dispersive X-ray spectroscopy (EDX). In red wine-colored ink, cubic titanium dioxide with a diameter of 110 to 200 nm was the major component, and rod-shaped iron oxide was rarely observed. Most of the ingredients of taupe yellow ink were rod-shaped yellow iron oxide, and a small amount of cubic titanium dioxide was observed. Red wine-colored ink and taupe yellow ink contained lumps composed of titanium dioxide particles. In red wine-colored ink, lumps were formed by agglomeration. However, we observed that the surface of the lump composed of titanium dioxide in the taupe yellow ink had a smooth surface caused by external physical compression. The titanium dioxide particle mass which found in taupe yellow ink in this study is an artificial product. When this mass accumulates in the dermis, it may cause a color mismatch. Therefore, permanent makeup using fine pigments should be free of foreign substances that may cause trouble in the skin. In addition, there is a need to improve the quality of the ink so that the required color can be safe and long lasting in the dermis.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.28 no.3
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• pp.63-71
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• 2014

A single-inverted-pendulum model is presented to simulate and predict the passive response of human balance control. This simplified biomechanical model was comprised of a torsional spring and damper, and a lump mass. An estimation of frequency response function was conducted to parameterize the complexity. The frequency domain identification method is used to identify the parameters of the model. The equivalent viscoelastic parameters of standing body were obtained and there was good conformity between the simulation and experimental result.

• Investigative Magnetic Resonance Imaging
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• v.15 no.2
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• pp.154-159
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• 2011

Testicular epidermoid cyst is a rare benign tumor, accounting for 1-2% of all testicular tumors. It can be cured by organ preserving surgery, so accurate preoperative diagnosis is very important for preventing unneccessary and extensive orchiectomy. We experienced a case of an 18-year-old man who presented with a painless lump in his right testis. The testicular mass showed an onion ring sign on ultrasonography. Computed tomography images showed the mass as a low attenuating lesion with curvilinear calcification. On Magnetic resonance imaging (MRI), the mass appeared as high signal intensity with internal alternating low signal intensity patterns on T2-weighted images. The mass was displayed as having homogeneous high signal intensity on diffusion magnetic resonance imaging and showed lower apparent diffusion coefficient values than normal testis parenchyma, similar to intracranial epidermoid cysts. Testicular MRI with DWI and ADC map can help to more accurately diagnose testicular epidermoid cyst.

• Journal of the Korean earth science society
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• v.30 no.5
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• pp.529-549
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• 2009

In 2007, just after the recession of the Changma, anomalously long rainy period (from July 30 to August 15) occurred in Korea. To identify the cause of the sustained rainy period, we performed synoptic analysis and the associated air motions. The behavior of each air parcel trajectory associated with atmospheric motion was then investigated. As a result, three particular phenomena occurring at latitudes lower than $40^{\circ}N$ were discovered. First, a mass of relatively cold air, referred to as E, made a deep intrusion from $20^{\circ}N$ to $60^{\circ}N$. Second, this intrusion was accompanied by another mass of air called dE. It was colder and drier than E and originated from the mid-troposphere over the tropical ocean. Third, dE and E rotated clockwise three times over a period of 17 days over the Northwestern Pacific and blocked the westerly waves imbedded in the zonal flow from propagating. Two additional phenomena were observed at latitudes higher than $40^{\circ}N$. First, the cold core system, while approaching from the west with low geopotential values at its center, was stagnated over Shanxi China. It enhanced the northward intrusion of dE and E, and then diminished. The subsequent low system showed similar evolution as the first one. Second, a warm core anticyclone was formed over Lake Baikal, blocking the westerlies for 13 days and contributed to the persistent northward incursion of warm moist air. Moreover, a horizontally extended intrusion of upper level clouds from the tropics to $50^{\circ}N$, which may be interpreted as a tropical plume, was found around the end of the period (from August 12 to 15, 2007) with successive tropical nights over Korea.

• Korean Journal of Head & Neck Oncology
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• v.25 no.2
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• pp.174-177
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• 2009

Parathyroid cyst are rare lesion of the neck and superior mediastinum. They are classified as either functional or nonfunctional based on the presence or absence of hyperparathyroidism. They typically present as a palpable neck mass, or as an incidental finding during neck surgery. So, it must be included within the differential diagnosis of a neck lump. A 48-year old woman was admitted to our hospital for evaluation of left anterior neck mass. Physical finding showed soft, movable, non-tender mass on the lower left third of the neck. Laboratory findings revealed normal thyroid function and normal serum calcium level. On previous history, patient underwent two times sono-guided fine needle aspiration at local clinic, and about 10cc clear watery aspirate was noted. Computerized tomography findings showed non-enhancing hypodense cystic lesion on left thyroid area with tracheal deviation to right side. Preoperative diagnosis was thyroid cyst, and thyroidectomy was planed. Intra-operative finding showed huge cystic mass occupying the left thyroid area and smooth, shiny, semitransparent thin cyst wall was noted, which was loosely attached to the thyroid. The cyst was easily dissected free from the thyroid and surrounding tissues. After cyst removal, pathological study confirmed as a parathyroid cyst.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.28 no.1
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• pp.24-30
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• 2004

Analysis model for the two-phase catalytic reactor is presented. With the progress in development of micro thermofluidic devices, needs fur understanding of the phenomena in two phase reaction in cm scale has been arisen. To investigate thermal and reactive performance of down scaled two phase reactor simple analysis model that is a kind of lumped flow model is proposed. Analysis model presented is based on the experiment on mm scale model reactor. Target experiment is catalytic decomposition of 70wt％ hydrogen peroxide with existence of perovskite L $a_{0.8}$S $r_{0.2}$Co $O_3$ catalyst. It is composed of balance equations of mass and energy. Each phase is considered to be a species fur the simplicity. Axial diffusion and transversal distribution of properties are neglected. Two phase catalytic reaction is modeled as successive gasification of liquid lump around catalyst and reaction in gas phase. Heat transfer is modeled by model function ofNu number. Modeled Nu is expressed as Nu=N $u_{0}$ (1＋ $a_1$( $a_2$ $T^{-}$ $a_3$)exp( $a_4$ $T^{-1}$)exp( $a_{5}$ z). Transfer coefficients are determined by the comparison of experimental results. With the model, heat transfer characteristics are investigated. Also by the mass transfer coefficient, characteristics in mass transfer is investigated. With the result basic understanding on design and analysis of mm scale two-phase reactive device is obtained. Also it can be further applied to micro scale reactive device fabricated by micromachining.ing..