• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2008년도 춘계학술대회 논문집
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• pp.163-164
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• 2008

• 한국자기학회:학술대회 개요집
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• 한국자기학회 1992년도 춘계연구발표회 논문개요집
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• pp.40-41
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• 1992

• Imaging Science in Dentistry
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• 제50권2호
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• pp.105-115
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• 2020

Purpose: This study investigated the position of the hyoid bone and its relationship with airway dimensions in different skeletal malocclusion classes using cone-beam computed tomography (CBCT). Materials and Methods: CBCT scans of 180 participants were categorized based on the A point-nasion-B point angle into class I, class II, and class III malocclusions. Eight linear and 2 angular hyoid parameters(H-C3, H-EB, H-PNS, H-Me, H-X, H-Y, H-[C3-Me], C3-Me, H-S-Ba, and H-N-S) were measured. A 3-dimensional airway model was designed to measure the minimum cross-sectional area, volume, and total and upper airway length. The mean crosssectional area, morphology, and location of the airway were also evaluated. Data were analyzed using analysis of variance and the Pearson correlation test, with P values <0.05 indicating statistical significance. Results: The mean airway volume differed significantly among the malocclusion classes(P<0.05). The smallest and largest volumes were noted in class II (2107.8±844.7 ㎣) and class III (2826.6±2505.3 ㎣), respectively. The means of most hyoid parameters (C3-Me, C3-H, H-Eb, H-Me, H-S-Ba, H-N-S, and H-PNS) differed significantly among the malocclusion classes. In all classes, H-Eb was correlated with the minimum cross-sectional area and airway morphology, and H-PNS was correlated with total airway length. A significant correlation was also noted between H-Y and total airway length in class II and III malocclusions and between H-Y and upper airway length in class I malocclusions. Conclusion: The position of the hyoid bone was associated with airway dimensions and should be considered during orthognathic surgery due to the risk of airway obstruction.

• 충청수학회지
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• 제22권2호
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• pp.229-234
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• 2009

Let f : $X{\rightarrow}X$ be a self-map of a connected finite polyhedron X. In this short note, we say that the mod H Nielsen number $N_H(f)$ is well-defined without the algebraic condition $ f_{\pi}(H)\;{\subseteq}H$ and that $N_H(f)$ is the same as the q-Nielsen number $N_q(f)$ in any case.

• Journal of applied mathematics & informatics
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• 제27권1_2호
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• pp.183-194
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• 2009

In this paper, we considered the following four-point boundary value problem $\{{x"(t)+h(t)f(t,x(t),x'(t))=0,\;0<t<1\atop%20x'(0)=ax(\xi),\;x'(1)=bx(\eta)}\$. where $0\;<\;{\xi}\;<\;{\eta}\;<\;1,\;{\delta}\;=\;ab{\xi}\;-\;ab{\eta}\;+\;a\;-\;b\;<\;0,\;0\;<\;a\;<\;\frac{1}{\xi},\;0\;<\;b\;<\;\frac{1}{\eta}$. After the discussion of the Green function of the corresponding homogeneous system, we establish some criteria for the existence of positive solutions by using the generalized Leggett-William's fixed point theorem. The interesting point is the expression of the Green function, which is a difficulty for multi-point BVP.

• Journal of the Korean Statistical Society
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• 제32권4호
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• pp.337-357
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• 2003

This paper introduces new measures for the stability of slope estimation on the second order response surface at a point and on a sphere. As a measure of point stability of slope estimation, we suggest a point dispersion measure of slope variances over all directions at a point. A spherical dispersion measure is also proposed as a measure of spherical stability of slope estimation on each sphere. Some designs are studied to explore the usefulness of the proposed measures. Using the point dispersion measure, another concept of slope rotatability called equally-stable slope rotatability is proposed as a useful property of response surface designs. We provide a set of conditions for a design to have equally-stable slope rotatability.

• 대한수학회지
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• 제56권6호
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• pp.1463-1474
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• 2019

Let C be a nonsingular projective curve of genus ${\geq}2$ over an algebraically closed field of characteristic 0. For a point P in C, the Weierstrass semigroup H(P) is defined as the set of non-negative integers n for which there exists a rational function f on C such that the order of the pole of f at P is equal to n, and f is regular away from P. A point P in C is referred to as a weak Galois-Weierstrass point if P is a Weierstrass point and there exists a Galois morphism ${\varphi}:C{\rightarrow}{\mathbb{p}}^1$ such that P is a total ramification point of ${\varphi}$. In this paper, we investigate the number of weak Galois-Weierstrass points of which the Weierstrass semigroups are generated by two positive integers.

• 센서학회지
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• 제9권3호
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• pp.153-162
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• 2000

평형수소 삼중점 (13.8033 K)부터 물의 삼중점 (273.16 K) 온도영역에서 표준온도계로 사용되는 캡슐형 백금저항온도계를 일차 교정하려면 고순도 물질의 삼중점이 사용된다. 국제온도눈금-1990 (ITS-90)을 확립하기 위해 평형수소, 네온, 산소, 아르곤, 수은 및 물의 삼중점 중에서 평형수소의 삼중점을 제외한 5 개의 삼중점을 실현하였다. 각각의 삼중점에서 국제비교용으로 채택된 캡슐형 백금저항온도계 2대의 저항을 2회 반복하여 측정하였다. 측정된 삼중점에서의 합성표준불확도는 A형 불확도와 B형 불확도 평가방법을 고려하여 산출하였다. 한국표준과학연구원에서 ITS-90에 정의된 네온, 산소, 아르곤, 수은 및 물의 삼중점에서의 합성표준불확도 추정결과는 각각 0.18 mK, 0.14 mK, 0.14 mK, 0.24 mK 및 0.11 mK 이었다.

• 상하수도학회지
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• 제33권5호
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• pp.395-404
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• 2019

The point-of-use water dispenser systems are widely used because of convenience in handling and demand for high-quality drinking water. The application has been increased recently in the public places such as department stores, universities and the rest areas in express ways. Improvement of water qualities by the dispenser systems was compared with tap water in this study. The tap water is supplied to the dispenser as the influent of the dispenser system. The twelve dispensers in the public places were used. The five dispensers used reverse osmosis as the main filter and other dispensers used various filters such as ultrafiltration, nanofiltration, and alumina filter. The water quality indicators for sanitation safety, i.e., turbidity and total coliforms, were evaluated. Other water qualities such as pH, residual chlorine, heterotrophic plate count (HPC), and total cell counts were also analyzed. By the point-of-use water dispenser, the turbidity, residual chlorine and pH were decreased and the HPC and total cell counts were increased. The t-test results revealed that the HPC of the tap waters were not significantly different from the treated waters but the total cell counts of the two groups were significantly different. The low pH of the RO filter treatment was also significantly different from the tap waters. This study will contribute to understand the role of the point-of-use water dispenser in improving water quality and to identify key water quality for the proper maintenance of the dispenser systems.

• 해양환경안전학회지
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• 제23권4호
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• pp.400-406
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• 2017

선박용 입형 편흡입 원심 해수펌프의 회전체와 파이프 시스템 내부에 발생한 과도한 손상의 원인을 분석하고자 실제 모델을 역설계 하였다. 이를 위해 전산유체역학(CFD)을 이용하여 해수냉각펌프의 내부유동 분석을 실시하였다. 결과적으로 역설계를 통한 대상펌프의 형상 및 경계조건을 설정하여 설계 운전점인 $125m^3/h$에서의 펌프 효율은 85.3 %, 양정 32.0미터로 계산되었다. 대상 펌프의 최고 효율점은 $150m^3/h$에서 약 86.2 %로 예측되었으나 실제 운전점과는 차이가 있었다. 최저 유량점인 $112.5m^3/h$에서는 저 유량점 특성상 유동이 불안정하여 해석의 수렴이 좋지 않았다. 선박에서 운전 중인 해수펌프 및 파이프 시스템 전반에 걸쳐 진행 중인 공동현상의 원인 규명을 통해 개선방안을 도출하고자 하였으나, 입 출구 전체 파이프 시스템의 계산, 각 지관들에 대한 유량 및 유속 측정 등을 통해 보다 명확한 원인분석을 위한 후속연구가 필요하다.