• 수면정신생리
• /
• 제1권2호
• /
• pp.172-181
• /
• 1994

Obstructive sleep apnea syndrome(OSAS) is most frequently diagnosed in the sleep laboratories and its severity is objectively estimated. In terms of treatment, the most prevalent method is the continuous positive airway pressure(CPAP) application as of now. However, in Korea, CPAP is still not sufficiently known and it is attributable to the fact that sleep study facilities have not been popularized. In this article, the authors present their own experience with CPAP in nine subjects with OSAS. In this study, CPAP was found to decrease stage 1 sleep and to increase stage 2 sleep, with increasing mean oxygen saturation and decreasing lowest oxygen saturation during nocturnal sleep. Also, it tended to increase sleep continuity and generally to improve sleep architecture. Rebound slow wave and/or REM sleep stages during CPAP were also noted in 8 out of 9 cases. The authors suggest that CPAP should be considered as the primary mode of treatment for patients with obstructive sleep apnea syndrome and related educational programs for physicians should be developed and provided by sleep specialists.

• Journal of applied mathematics & informatics
• /
• 제32권1_2호
• /
• pp.75-82
• /
• 2014

In this paper, we consider the periodic boundary value problem with sign changing nonlinearity $$u^{{\prime}{\prime}{\prime}}+{\rho}^3u=f(t,u),\;t{\in}[0,2{\pi}]$$, subject to the boundary value conditions: $$u^{(i)}(0)=u^{(i)}(2{\pi}),\;i=0,1,2$$, where ${\rho}{\in}(o,{\frac{1}{\sqrt{3}}})$ is a positive constant and f(t, u) is a continuous function. Using Leggett-Williams fixed point theorem, we provide sufficient conditions for the existence of at least three positive solutions to the above boundary value problem. The interesting point is the nonlinear term f may change sign.

• 한국IT서비스학회지
• /
• 제14권3호
• /
• pp.131-146
• /
• 2015

The communications market can be characterized for its overflow of users, oligopoly business structure, 24/7 open service, incomplete sales, and operation of core platform function. These characteristics have lead users to continuously make complaints and suffer inconveniences, and thus the concept of user protection has come to receive attention. This study aims to propose solutions through communication channeling between businesses and users, based on website construction from the viewpoint of user protection. In particular, a research model was developed to display how the information symmetry of websites can be influential on the satisfaction, reliability, and continuous intention for using communication services. Total of 14 hypotheses were set to measure a significant degree of variables corelation and eight hypotheses were accepted finally. The analysis results showed that information symmetry of telecommunication service websites had a positive effect on intention for continuous usage. Through the research results, it is expected that communication service businesses will be able to consider important factors when constructing websites. Furthermore, the results are expected to be utilized as for ensuring users' continued usage of their communication services.

• 충청수학회지
• /
• 제20권4호
• /
• pp.411-418
• /
• 2007

Let $X_1$, ${\cdots}$, $X_n$ be nondegenerate and positive independent identically distributed(i.i.d.) random variables with common absolutely continuous distribution function F(x) and $E(X^2)$ < ${\infty}$. The random variables $X_1+{\cdots}+X_n$ and $\frac{X_1+{\cdots}+X_m}{X_1+{\cdots}+X_n}$are independent for 1 $1{\leq}$ m < n if and only if $X_1$, ${\cdots}$, $X_n$ have gamma distribution.

• 한국수학교육학회지시리즈B:순수및응용수학
• /
• 제5권2호
• /
• pp.156-162
• /
• 1998

The main objective of this paper is to study the boundedness of solutions of the differential equation $L_{n} {\chi}＋F(t,{\chi}) = f(t), n {\geq} 2 $(*) Necessary and sufficient conditions for boundedness of all solutions of (*) will be obtainded. The asymptotic behavior of solutions of (*) will also be studied.

• 충청수학회지
• /
• 제27권2호
• /
• pp.157-163
• /
• 2014

Let {$X_i$, $1{\leq}i{\leq}n$} be a sequence of i.i.d. sequence of positive random variables with common absolutely continuous cumulative distribution function F(x) and probability density function f(x) and $E(X^2)$ < ${\infty}$. The random variables X + Y and $\frac{(X-Y)^2}{(X+Y)^2}$ are independent if and only if X and Y have gamma distributions. In addition, the random variables $S_n$ and $\frac{\sum_{i=1}^{m}(X_i)^2}{(S_n)^2}$ with $S_n=\sum_{i=1}^{n}X_i$ are independent for $1{\leq}m$ < n if and only if $X_i$ has gamma distribution for $i=1,{\cdots},n$.

• 대한한방내과학회지
• /
• 제38권5호
• /
• pp.548-554
• /
• 2017

Objective: A general prejudice exists that all herbal medicines are not good for liver. We report that herbal medicine can have positive effects on the liver, based on the improved liver function test levels observed in one patient. We also suggest the effectiveness of co-administration of herbal and western medicines. Methods: We checked the liver function test levels of one patient measured on 12 July at another hospital. We identified worse levels on 7 August, when he was first admitted to Semyung University Hospital. We measured liver function test levels of the same patient after treatment with Korean herbal medicine on 14 and 21 August during hospitalization at Semyung Hospital. We compared the figures and evaluated the effectiveness of 'Saenggangeonbi-tang' herbal medicine in the liver. Results: The patient's liver function test levels were normal on 12 July, but had become abnormal by 7 August, when he was admitted to Semyung Hospital. The cause of liver dysfunction was suggested as Atorvastatin, one of the western drugs he had started to take. Continuous treatment with Korean herbal medicine resulted in a definite improvement in liver function. Conclusion: Korean herbal medicine can provide positive improvements in liver function test levels.

• 한국전산구조공학회:학술대회논문집
• /
• 한국전산구조공학회 1999년도 봄 학술발표회 논문집
• /
• pp.78-85
• /
• 1999

In this study, I-type girders used as main members of a two span continuous steel bridge, are optimally designed by a Load and Resistance Factor Design method(LRFD) using an numerical optimization method. The width, height web thickness and flange thickness of the main girder are set as design variables, and light weight design is attempted by choosing the cross-sectional area as an object function. The main program is coded with C++ and connected with optimization modul ADS, which is coded with FORTRAN. The results of the program show that the stress constraints of noncomposite section during the initial construction stage become active in the positive moment area and the service limit state constaints become active in the negative moment area.

• Asia Marketing Journal
• /
• 제18권3호
• /
• pp.47-63
• /
• 2016

Rational choice theory holds that the alternative with largest expected utility in the choice set should always be chosen. However, it is often observed that an alternative with the largest expected utility is not always chosen while the choice task itself being avoided. Such a choice phenomenon cannot be explained by the traditional expected utility maximization principle. The current study posits shows that such a phenomenon can be attributed to the gap between the expected perceived gain (or loss) and the expected perceived value. This study mathematically analyses the relationship between the expectation of an alternative's gains or losses over the reference point and its expected value, when the perceived gains or losses follow continuous probability distributions. The proposed expected value (EV) function can explain the effects of loss aversion and uncertainty on the evaluation of an alternative based on the prospect theory value function. The proposed function reveals why the expected gain of an alternative should exceed some positive threshold in order for the alternative to be chosen. The model also explains why none of the two equally or similarly attractive options is chosen when they are presented together, but either of them is chosen when presented alone. The EV function and EG-EV curve can extract and visualize the core tenets of the prospect theory more clearly than the value function itself.

• 대한임상검사과학회지
• /
• 제45권4호
• /
• pp.159-163
• /
• 2013

To investigate the cognitive degree about hepatitis and hepatosis, 916 subjects are examined with query and hepatotitis B, C, E test as well as s-AST and s-ALT as liver function test. Based on results, there are 4.9% of positive hepatitis and 8.9% of hepatosis and 13.8% of liver disorder. Among positive hepatitis, there are 93.3% of type B, 42.2% of type E and 6.7% of type C, respectively. From 45% of positive hepatitis B, they carry hepatitis B and E together. The cognitive degree about positive hepatitis is 64.4%, hepatosis 8.6%. The knowledge degree from cognitive group is higher than that of noncognitive group but there is no difference from hepatosis between two groups (p<0.001). The cognitive degree of liver disorder depends on academic background (p<0.001), mother's academic background (p<0.001), job (p<0.05) and family's income (p<0.001), showing significant difference. In summary, hepatitis carrier aware quite well about liver disorder but very low from hepatosis. Accordingly, the plan to increase a cognitive degree and continuous education as well as policy support to minimize spread of disease and to protect not to be worsen disease will be needed.