• 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.

• The Korean Journal of Physiology and Pharmacology
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• v.9 no.2
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• pp.103-108
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• 2005

To study the direct effect of somatostatin (SS) on calcium channel current ($I_{Ba}$) in guinea-pig gastric myocytes, $I_{Ba}$ was recorded by using whole-cell patch clamp technique in single smooth muscle cells. Nicardipine ($1{\mu}M$), a L-type $Ca^{2+}$ channel blocker, inhibited $I_{Ba}$ by $98{\pm}1.9$% (n=5), however $I_{Ba}$ was decreased in a reversible manner by application of SS. The peak $I_{Ba}$ at 0 mV were decreased to $95{\pm}1.5$, $92{\pm}1.9$, $82{\pm}4.0$, $66{\pm}5.8$, $10{\pm}2.9$% at $10^{-10}$, $10^{-9}$, $10^{-8}$, $10^{-7}$, $10^{-5}$ M of SS, respectively (n=3∼6; $mean{\pm}SEM$). The steady-state activation and inactivation curves of $I_{Ba}$ as a function of membrane potentials were well fitted by a Boltzmann equation. Voltage of half-activation ($V_{0.5}$) was $-12{\pm}0.5$ mV in control and $-11{\pm}1.9$ mV in SS treated groups (respectively, n=5). The same values of half-inactivation were $-35{\pm}1.4$ mV and $-35{\pm}1.9$ mV (respectively, n=5). There was no significant difference in activation and inactivation kinetics of $I_{Ba}$ by SS. Inhibitory effect of SS on $I_{Ba}$ was significantly reduced by either dialysis of intracellular solution with $GDP_{\beta}S$, a non-hydrolysable G protein inhibitor, or pretreatment with pertussis toxin (PTX). SS also decreased contraction of guinea-pig gastric antral smooth muscle. In conclusion, SS decreases voltage-dependent L-type calcium channel current ($VDCC_L$) via PTXsensitive signaling pathways in guinea-pig antral circular myocytes.

• The Korean Journal of Pharmacology
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• v.30 no.2
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• pp.227-242
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• 1994

The general pharmacological effects of a new anthracycline anticancer agent, DA-125 $[7-0-(2,\;6-dideoxy-2-fluoro-{\alpha}-L-talopyranosyl)-adriamycinone-14-{\beta}-alaninate{\cdot}HCI]$ were investigated in mice, rats, guinea pigs, rabbits and dogs. Intravenous administration of DA-125 presented no significant effects on the central and peripheral nervous systems of ICR mice except a decrease in the numbers of acetic acid-induced writhing response at a dose of 10 mg/kg. In anesthetized rats and dogs, DA-125 produced a transient depression of blood pressure and an increase in heart rate, but did not affect the peripheral blood flow in the isolated ear vessels of rabbits and the mechanical functions of the isolated hearts of guinea pigs. No significant effects were observed on the gastrointestinal functions and the contractilities of smooth muscle preparations obtained from guinea pig trachea, rabbit ileum, pregnant and non-pregnant uterus and vas deferens of rats. DA-125 Increased the contractility of the isolated ileum of guinea pigs in a dose range of $10^{-6}{\sim}10^{-9}g/ml$, and also increased, but weaker than adriamycin, the vascular permeability in rat skin. DA-125 had no effect on the kallikrein-induced increase in permeability and the permeability of the visceral organs. DA-125 did not adversely affect the liver function and the blood coagulation system, and did not induce hemolysis in vitro. It is concluded from the results that the general pharmachological effects of DA-125 are similar to or weaker than those of adriamycin, and that little adverse effects are anticipated with a therapeutic dose range.

• Journal of the Korean institute of surface engineering
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• v.53 no.6
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• pp.351-359
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• 2020

Formation behavior and properties of PEO (Plasma Electrolytic Oxidation) film on AA2024 were investigated under application of pulsed current as a function of Na3PO4 concentration in 0.05 M Na2SiO3 solution by analyzing voltage-time behavior, in-situ observation of arc generation, observation of surface morphology and measurements of thickness and surface roughness. Arc generation voltage decreased with increasing Na3PO4 concentration. Color difference of PEO films between edge and inner part disappeared by addition of Na3PO4. It was also observed that size of nodules on PEO film decreased with increasing Na3PO4 concentration. Thickness of PEO films formed on AA2024 increased with increasing Na3PO4 concentration. Whereas, surface roughness of PEO films decreased with increasing Na3PO4 concentration up to 0.05 M of Na3PO4 which is attributed to the deceased size of nodules on the PEO films. However, the surface roughness increased with increasing Na3PO4 concentration more than 0.07 M of Na3PO4 which seems to be due to the formation of non-uniform PEO films with smooth surface and large size pores formed by orange-colored big arcs. The experimental results suggest that added sodium phosphate less than 0.2 M in an alkaline silicate solution can contribute to the formation of relatively thick and uniform thickness of PEO films under arc generation voltage lower than 300 V.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.23 no.11
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• pp.1397-1406
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• 2019

In everyday mobile phone calls between the disabled and non-disabled people due to neurological impairment, the communication accuracy is often hindered by combining the accuracy of pronunciation due to the neurological impairment and the pronunciation features of the disabled. In order to improve this problem, the limiting method is MEMS (micro electro mechanical systems), which includes an induction line that artificially corrects difficult vocalization according to the oral characteristics of the language impaired by improving the word of out of vocabulary. mechanical System) Microphone device improvement. S/W improvement is decision tree with invert function, and improved matrix-vector rnn method is proposed considering continuous word characteristics. Considering the characteristics of H/W and S/W, a similar dictionary was created, contributing to the improvement of speech intelligibility for smooth communication.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.485-488
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• 2005

Most metals are polycrystalline material whose deformation is dominated by the slip system. During the deformation process, orientation of slip systems is rearranged with preferred orientations, leading to deformation-induced crystallographic texture which is called deformation texture. Depending on the texture development, the property of material can be changed. The rate-independent crystal plasticity which is based on the Schmid law as a yield function causes a non-uniqueness in the choice of active slip systems. In this work, to avoid the slip system ambiguity problem, rate-independent crystal plasticity model based on the smooth yield surface with rounded-off corners is adopted. In order to simulate the polycrystalline material under plastic deformation, we employ the Taylor model of polycrystal behavior that all the grains are assumed to be subjected to the macroscopic velocity gradient. Rigid-plastic finite element program based on this rate-independent crystal plasticity is developed to predict the grain-level deformation behavior of FCC metals during metal forming processes. In the finite element calculation, one integration point is considered as a crystalline aggregate which has a number of crystals. Macroscopic behavior of material can be deduced from the behavior of aggregates. As applications, the extrusion processes are simulated and the changes of mechanical properties are predicted.

• Journal of the Korean Data and Information Science Society
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• v.28 no.6
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• pp.1229-1244
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• 2017

In recent years, as demand for data-based analytical methodologies increases in various fields, optimization methods have been developed to handle them. In particular, various constraints required for problems in statistics and machine learning can be solved by convex optimization. Alternating direction method of multipliers (ADMM) can effectively deal with linear constraints, and it can be effectively used as a parallel optimization algorithm. ADMM is an approximation algorithm that solves complex original problems by dividing and combining the partial problems that are easier to optimize than original problems. It is useful for optimizing non-smooth or composite objective functions. It is widely used in statistical and machine learning because it can systematically construct algorithms based on dual theory and proximal operator. In this paper, we will examine applications of ADMM algorithm in various fields related to statistics, and focus on two major points: (1) splitting strategy of objective function, and (2) role of the proximal operator in explaining the Lagrangian method and its dual problem. In this case, we introduce methodologies that utilize regularization. Simulation results are presented to demonstrate effectiveness of the lasso.

• Journal of The Korean Astronomical Society
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• v.46 no.3
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• pp.125-131
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• 2013

We present the relation between the genus in cosmology and the Betti numbers for excursion sets of three- and two-dimensional smooth Gaussian random fields, and numerically investigate the Betti numbers as a function of threshold level. Betti numbers are topological invariants of figures that can be used to distinguish topological spaces. In the case of the excursion sets of a three-dimensional field there are three possibly non-zero Betti numbers; ${\beta}_0$ is the number of connected regions, ${\beta}_1$ is the number of circular holes (i.e., complement of solid tori), and ${\beta}_2$ is the number of three-dimensional voids (i.e., complement of three-dimensional excursion regions). Their sum with alternating signs is the genus of the surface of excursion regions. It is found that each Betti number has a dominant contribution to the genus in a specific threshold range. ${\beta}_0$ dominates the high-threshold part of the genus curve measuring the abundance of high density regions (clusters). ${\beta}_1$ dominates the genus near the median thresholds which measures the topology of negatively curved iso-density surfaces, and ${\beta}_2$ corresponds to the low-threshold part measuring the void abundance. We average the Betti number curves (the Betti numbers as a function of the threshold level) over many realizations of Gaussian fields and find that both the amplitude and shape of the Betti number curves depend on the slope of the power spectrum n in such a way that their shape becomes broader and their amplitude drops less steeply than the genus as n decreases. This behaviour contrasts with the fact that the shape of the genus curve is fixed for all Gaussian fields regardless of the power spectrum. Even though the Gaussian Betti number curves should be calculated for each given power spectrum, we propose to use the Betti numbers for better specification of the topology of large scale structures in the universe.

• Tuberculosis and Respiratory Diseases
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• v.46 no.3
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• pp.317-326
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• 1999

Background: Neural control of airway function is through parasympathetic, sympathetic and non-adrenergic, non-cholinergic mechanisms. The autonomic nervous system controls the airway smooth muscle tone, mucociliary system, permeability and blood flow in the bronchial circulation and release of mediators from the mast cells and other inflammatory cells. The cardiovascular and respiratory autonomic efferent fibers have a common central origin, so altered cardiovascular autonomic reflexes could reflect the altered respiratory autonomic status. Therefore, we performed this study to assess the autonomic abnormality and determine the correlating factors of severity of autonomic neuropathy in patients with chronic obstructive pulmonary disease(COPD) using easily reproducible cardiovascular autonomic reflex function test. Method: The study included 20 patients with COPD and 20 healthy persons obtained on Health Promotion Center in Yeungnam university hospital. All the patients had history and clinical features of COPD as defined by the American Thoracic Society. Any patients with myocardial ischemia, cardiac arrythmia, hypertension, central or peripheral nervous system disease, diabetes mellitus, or any other diseases known to produce autonomic neuropathy, has excluded. The autonomic nervous system function tests included three tests evaluating the parasympathetic system and two tests evaluating the sympathetic system. And also all subjects were subjected to pulmonary function test and arterial blood gas analysis. Results: Autonomic dysfunction was more commonly associated with patients with COPD than healthy person The parasympathetic dysfunction was frequent in patient with COPD, but sympathetic dysfunction seemed preserved. The severity of parasympathetic dysfunction in patients with COPD was correlated with the degree of duration of disease, smoking, reductions in the value of $FEV_1$ and FVC, and arterial hypoxemia but no such correlation existed for age, type of COPD, $FEV_1$/FVC, or $PaCO_s$. Conclusion: There is high frequency of parasympathetic dysfunction associated with COPD and the parasympathetic abnormality in COPD is increased in proportion to severity of airway disease. In COPD, parasympathetic dysfunction probably does not the cause of disease, but it may be an effect of disease progression.

• Proceedings of the Korean Vacuum Society Conference
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• 1999.07a
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• pp.58-58
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• 1999

The diamond films which can be applied to SOD (silicon-on-diamond) structure were deposited on Si(100) substrate using CO/H2 CH4/H2 source gases by microwave plasma chemical vapor deposition(MPCVD), and SOD structure have been fabricated by poly-silicon film deposited on the diamond/Si(100) structure y low pressure chemical vapor deposition(LPCVD). The phase of the diamond film, surface morpholog, and diamond/Si(100) interface were confirmed by X-ray diffraction(XRD), scanning electron microscopy(SEM), atomic force microscopy(AFM), and Raman spectroscopy. The dielectric constant, leakage current and resistivity as a function of temperature in films are investigated by C-V and I-V characteristics and four-point probe method. The high quality diamond films without amorphous carbon and non-diamond elements were formed on a Si(100), which could be obtained by CO/H2 and CH4/H2 concentration ratio of 15.3% and 1.5%, respectively. The (111) plane of diamond films was preferentially grown on the Si(100) substrate. The grain size of the films deposited by CO/H2 are gradually increased from 26nm to 36 nm as deposition times increased. The well developed cubo-octahedron 100 structure nd triangle shape 111 are mixed together and make smooth and even film surface. The surface roughness of the diamond films deposited by under the condition of CO/H2 and CH4/H2 concentration ratio of 15.3% and 1.5% were 1.86nm and 3.7 nm, respectively, and the diamond/Si(100) interface was uniform resistivity of the films deposited by CO/H2 concentration ratio of 15.3% are obtained 5.3, 1$\times$10-9 A/cm, 1 MV/cm2, and 7.2$\times$106 $\Omega$cm, respectively. In the case of the films deposited by CH4/H2 resistivity are 5.8, 1$\times$10-9 A/cm, 1 MV/cm, and 8.5$\times$106 $\Omega$cm, respectively. In this study, it is known that the diamond films deposited by using CO/H2 gas mixture as a carbon source are better thane these of CH4/H2 one.