• Journal of Environmental Science International
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• v.21 no.11
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• pp.1339-1348
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• 2012

The versatile aerosol concentration enrichment system (VACES) have proven useful for providing elevated levels of atmospheric aerosol to human and animal exposures. In this study, we describe a VACES and tests conducted to both optimize the enhancement factor (EF) and characterize how it depends on experiment conditions. Particle number concentrations were measured from upstream and downstream of the system by scanning mobility particle sizer (SMPS) with a long differential mobility analyzer (DMA) in combination with a condensation particle counter (CPC). SMPS was used for to determine VACES particle EF. Particle EF tends to increase for higher the saturator temperature ($T_{Sat}$) and lower the condenser temperature ($T_{Con}$). $T_{Con}$ higher than $0^{\circ}C$ and $T_{Sat}$ lower than $50^{\circ}C$ was the best to obtain the most increase in particle concentration. Correlation analysis of EF with factor variables of $T_{Sat}$ and $T_{Con}$ resulted in correlation 0.662 and 0.416, respectively. With all five predictor variables included in a multiple regression model, the EF had a liner correlation with $R^2=0.643$.

• Journal of the Korean Mathematical Society
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• v.49 no.3
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• pp.641-658
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• 2012

The goal of this paper is to develop a nonlinear observer-based control strategy for a multi-variables continuous stirred tank reactor (CSTR). A new robust nonlinear observer is constructed to estimate the whole process state variables. The observer is coupled with a nonlinear controller, designed based on the input-output linearization for controlling the concentration and reactor temperature. The closed loop system is shown to be globally asymptotically stable based on Lyapunov arguments. Finally, computer simulations are developed for showing the performance of the proposed controller.

• Journal of the Korean Society of Clothing and Textiles
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• v.15 no.1
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• pp.48-60
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• 1991

The purpose of this study is to analyze the pattern of human developmental growth with empirical anthropometric data for clothing construction. The sample was drawn randomly out of senior high school boys and girls in seoul urban area. The sample size was 424 boys and 301 girls between age 16 and 18. Dependent variables of this study were modified after extraction of common variables from raw data. 42 dependent variables were analyzed by the method of Duncan Test as Multiple Range Test among three age groups and T-Test between male and female of same age groups. The analysis of these data was carried with spss-x package by the computer installed in INHA University. The major findings can be summarized as follows. 1. In Duncan Test, female students between age 16 and 18 were not significantly different in the majority of dependent variables, but girth measurements and weight of 17 and 18 age groups were significantly different from that of 16 age groups. 2. In Duncan Test, male students were significantly different in the majority of the dependent variables, especially 33 variabls from 42 variables, among three age groups. 3. In T-Test, hip girth was only not significantly different between male and female and neck girth of the female students was only significantly larger than that of the male students.

• Proceedings of the KIEE Conference
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• 1990.07a
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• pp.433-436
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• 1990

An optimal Stabilization technique for a bilinear in duction model is introduced. This technique includes to o parts; the one is an stabilization control using Lyap unov Function which has the form of a sum of linear and quadratic function of the state variables, and the other is an optimal control using the performance index which depends on the choice of the elements of the Ly apunov matrices concerning both the state variables and the input variables. Therefore, induction motor is drived with the shorter transient time of the state variables and with the smaller overshoot of the ones, simulation results are obtained from a digital computer. Experimental ones are obtained from implementation of the optimizing controller using 8086 microprocessor kits and analog circuits are compared.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.6 no.8
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• pp.63-71
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• 1983

Aggregate planning coordinate the control variable over long-term to apply a demand variable and forcasting. In order to necessary the goal that doesn't make an inter-contradiction and explicitly defined. We made a considerable point of system approach for scheduling establishment. It include the control variables of aggregate planning : 1) employment 2) over time working and idle time 3) inventory 4) delivery delay S) subcontract 61 long - term facility capacity. Each variables composed of pure strategy as like a decision of inventory level, a change of employment level, etc. md alternative costs make a computation on the economic foundation. But the optimum alternative costs represent the mixed pure strategy. The faults of this method doesn't optimum guarantee a special scheduling as well as increasing a number of alternative combination. Theoretical, Linear Decision Rule make an including all variables, but it is almost impossible for this model to develope actually And also make use of the aggregate planning problem for developing system approach : LDR, heuristic model, Search Decision Rule, all kind of computers, simulation. But these models are very complex, each variables get an extremely inter-dependence. So this study be remained by theory level, some approach methods has not been brought the optimum solution to apply in every cases.

• Journal of Physiology & Pathology in Korean Medicine
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• v.21 no.6
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• pp.1601-1610
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• 2007

The purpose of this study was to determine whether a pulse analyzer was useful 1) to characterize the variables of pulse wave of diabetes mellitus group, compared with those of healthy subjects, and 2) to determine Sasang Constitution in diabetes mellitus group and healthy subjects. 1. The sum of pulse pressure (energy) and the ratio of systolic period area (As%), called pulse pressure-related variables, were higher in diabetes mellitus group than healthy group, while the height of dicrotic wave (h5) and the ratio of height of dicrotic wave to height of percussion wave (h5/h1), correlated with arterial compliance, were lower in diabetes mellitus group than healthy group. 2. Taeumin of diabetes mellitus group showed higher pressure-related variables than that of healthy group. 3. Soumin of diabetes mellitus group had shorter the time to dicrotic wave (t5) than that of healthy group. 4. Soyangin of diabetes mellitus group showed higher heart rates and lower values in pulse wave time-related variables, including time to dicrotic wave(t5), time to incisura (t4), total time minus time to incisura (t-t4), total time (t), width of percussion wave (w), and the ratio of width of percussion wave to total time (w/t), than that of healthy group. 5. Contact pressure (CP), sum of pulse pressure (energy), height of pre-incisura (h2), height of incisura (h4), width of percussion wave (w), time to incisura (t4), time to percussion wave (t1), variance of total time (Vt), variance of height of percussion wave(Vp) and the ratio of height of incisura to height of percussion wave (h4/h1) were used to develop the rules of Sasang Constitution Classification with about seventy five percents accuracy. These suggested that the pulse analyzer was useful to evaluate the risk degree of diabetes mellitus and to determine Sasang Constitution among either diabetes mellitus group or healthy group.

• Journal of Korean Academy of Nursing
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• v.34 no.5
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• pp.781-790
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• 2004

Purpose: The purpose of this study was to develop a model of an elderly health promotion center after witnessing the effect of a social support program on dependent variables in older adults at a local community health center. Method: The subjects were 60 female adults over 65 years dwelling in a rural area, and they were divided into experimental and control groups each with 30 people. A social support program was implemented 6 hours a day, 3 times a week, for 4 months in the experimental group. Included was health assessment, health education, counseling, consultation, exercise, physical & occupational therapy, primary care, recreation, lunch & transfer service. Data was collected from May 1stto September 14th, 2002 by questionnaires, and analyzed by $x^2$-test, t-test, Pearson's correlation coefficient and stepwise multiple regression using SAS. Result: The social support program in the elderly was very effective on all dependent variables of physical health (t=4.68, p=.001), health knowledge (t=3.60, p=.001), life satisfaction (t=8.65, p=.001), and health promoting behaviors (t=5.23, p=.001). Conclusion: The Social Support Program at a Community Health Center was effective on health promoting behaviors in the elderly.

• Journal of the Korean Statistical Society
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• v.25 no.1
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• pp.153-159
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• 1996

Sums of independent random variables $S_n = X_1 + X_ + cdots + X_n$ are considered, where the X$_{n}$ are chosen according to a stationary process of distributions. Given the time t .geq. O, let N (t) be the number of indices n for which O < $S_n$ $\geq$ t. In this set up we prove that N (t)/t converges almost surely and in $L^1$ as t longrightarrow $\infty$, which generalizes classical renewal theorem.m.

• Proceedings of the Korean Statistical Society Conference
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• 2002.05a
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• pp.49-54
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• 2002

For arbitrary random variables {$X_{n},n{\geq}1$}, the order of growth of the series. $S_{n}\;=\;{\sum}_{j=1}^n\;X_{j}$ is studied in this paper. More specifically, when the series S_{n}$ diverges almost surely, the strong law of large numbers $S_{n}/g_{n}^{-1}$($A_{n}{\psi}(A_{n}))\;{\rightarrow}\;0$ a.s. is constructed by extending the results of Petrov (1973). On the other hand, if the series $S_{n}$ converges almost surely to a random variable S, then the tail series $T_{n}\;=\;S\;-\;S_{n-1}\;=\;{\sum}_{j=n}^{\infty}\;X_{j}$ is a well-defined sequence of random variables and converges to 0 almost surely. For the almost surely convergent series $S_{n}$, a tail series strong law of large numbers $T_{n}/g_{n}^{-1}(B_{n}{\psi}^{\ast}(B_{n}^{-1}))\;{\rightarrow}\;0$ a.s., which generalizes the result of Klesov (1984), is also established by investigating the duality between the limiting behavior of partial sums and that of tail series. In particular, an example is provided showing that the current work can prevail despite the fact that previous tail series strong law of large numbers does not work.

• Child Health Nursing Research
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• v.20 no.4
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• pp.314-321
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• 2014

Purpose: This study was conducted to identify factors affecting mental health and behavioral problems among high school students through the lens of a Social Cognitive Career Theory. Methods: A descriptive study was carried out with 384 high school students in Seoul, Korea. A self-administrative questionnaire was used. It consisted of items on person background variables, career-related variables including career barriers, learning experiences, self-efficacy, outcome expectations, and career indecision, and mental health and behavioral problems. Descriptive statistics, correlation analysis and multiple regression analysis were performed using the SPSS 21.0 program. Results: The results showed that perceived stress (t=5.12, p<.001), perceived health status (t=-4.08, p=.002), and school record (t=5.46, p<.001) were statistically significant variables. Also, career barriers (t=10.57, p<.001) was a significant factor influencing mental health and behavioral problems. Conclusion: These findings indicate that among career-related variables, career barrier needs to be considered for preventive and therapeutic approach to mental health and behavioral problems in adolescents. Furthermore, the results suggest that career-related stress level should be assessed in high school students on a regular basis.