• Korean Journal of Adult Nursing
• /
• v.25 no.5
• /
• pp.549-558
• /
• 2013

Purpose: The purpose of this study was to identify impact of stress on depression among university students and the moderating effect of social support in the relationship between stress and depression in university students. Methods: A total of 445 subjects were participated from May to July 2011. Data were collected by self-reported questionnaires and t-test, ANOVA, and stepwise multiple regression with SPSS/WIN 20.0 were used to analyze the data. Results: The results indicate that depression was increased by stress and decreased with social support. Social support included four type of social support behavior; emotional support, informational support, material support, and appraisal support. Multiple regression analysis showed that moderating effect of emotional support was significant when provided by friends but not by parents. Conclusion: These finding indicate the importance of emotional support of friends on depression in university students.

• Journal of Applied Biological Chemistry
• /
• v.44 no.4
• /
• pp.177-179
• /
• 2001

Traditional wet chemical methods for testing of soil properties require extensive time and labor, and cause the discharge of pollutants, making them undesirable for routine soil analyses. This research was conducted to improve the accuracy of soil properties in soil fertility assessments. A total of 140 finely ground soil samples were used to obtain accurate calibrations and validation for estimating soil moisture, OM, and T-N. Finely ground soil samples satisfied the improved accuracy for routine NIR measuring of the field soils. The results indicated that NIR spectroscopy could be used as a routine method for quantitatively determining OM, moisture, and T-N of field soil, although this technique requires many combinations of sample pretreatments and data manipulations to obtain optimal predictions.

• Journal of the Korean Data and Information Science Society
• /
• v.21 no.1
• /
• pp.51-59
• /
• 2010

In the case that the regression function has a discontinuity point in generalized linear model, Huh (2009) estimated the location and jump size using the log-likelihood weighted the one-sided kernel function. In this paper, we consider estimation of the unknown number of the discontinuity points in the regression function. The proposed algorithm is based on testing of the existence of a discontinuity point coming from the asymptotic distribution of the estimated jump size described in Huh (2009). The finite sample performance is illustrated by simulated example.

• Journal of the Korean Data and Information Science Society
• /
• v.13 no.2
• /
• pp.77-85
• /
• 2002

The statistical testing methods have been widely recognized to determine the plain and cipher texts. In fact, the randomness for a sequence from an encryption algorithm is necessary to guarantee security and reliance of cipher algorithm. Thus, the statistical randomness tests are used to discover cipher text. In this paper, we would provide the critical value for an approximate entropy test by estimating the nonlinear regression equation when the number of sequence and the level of significance are given. Thus, we can discern plan and cipher text for real problem with given number of sequence and the level of significance. Also, we confirm the fitness of the estimated critical values from the rate of success for plain or cipher text.

• Journal of Korean Society for Quality Management
• /
• v.21 no.2
• /
• pp.162-169
• /
• 1993

For the problem of testing the parallelism of several regression lines against ordered alternatives, two test statistics and proposed and examined. The proposed statistics are linear combinations of robust estimators of slope parameters, which are modifications of the Adichie (1976) test based on scores. The asymptotic null variances of the proposed states tics are estimated by the kernel density estimation methods. The proposed tests are compared with the Adichie's test in terms of asymptotic relative efficiency and small-sample powers.

• The Korean Journal of Applied Statistics
• /
• v.8 no.2
• /
• pp.77-86
• /
• 1995

For the problem of testing the parallelism of two regression lines, a robust procedure is proposed and examined. The proposed test statistic is based on the one-step GM-estimators of slope parameters proposed by Song et al. (1994b). These GM-estimators used the Least Trimmed Squares estimates as an initial values so as to obtain high breakdown point. Through a small-sample Monte Carlo simulation the empirical levels and powers of the proposed test are compared with other tests under various error distributions.

• The Korean Journal of Applied Statistics
• /
• v.11 no.1
• /
• pp.97-111
• /
• 1998

This paper suggests a Bayesian method for testing first-order markov correlation among linear regression disturbances. As a Bayesian test criterion, Bayes factor is derived in the form of generalized Savage-Dickey density ratio that is easily estimated by means of posterior simulation via Gibbs sampling scheme. Performance of the Bayesian test is evaluated and examined based upon a Monte Carlo experiment and an empirical data analysis. Efficiency of the posterior simulation is also examined.

• Proceedings of the KIEE Conference
• /
• 2006.10c
• /
• pp.211-213
• /
• 2006

In this study, plasma etching process was modeled by using support vector machine (SVM). The data used in modeling were collected from the etching of silica thin films in inductively coupled plasma. For training and testing neural network, 9 and 6 experiments were used respectively. The performance of SVM was evaluated as a function of kernel type and function type. For the kernel type, Epsilon-SVR and Nu-SVR were included. For the function type, linear, polynomial, and radial basis function (RBF) were included. The performance of SVM was optimized first in terms of kernel type, then as a function of function type. Five film characteristics were modeled by using SVM and the optimized models were compared to statistical regression models. The comparison revealed that statistical regression models yielded better predictions than SVM.

• International Commerce and Information Review
• /
• v.11 no.2
• /
• pp.329-342
• /
• 2009

The purpose of this study was to identify the issues which how situational constraints of negotiation affect outcomes. To achieve the purpose of this research, a multiple regression model was set up to identify the relationships between situational constraints of negotiation and negotiation outcome on international trade contracts. To implement the study, empirical questionnaires were collected from Korean business men who have actually conducted international trade with foreign firms. Reliability analysis and factor analysis were used to assess the reliability and validity of research variables. and multiple regression analysis were used for testing the relationships between situational constraints of negotiation and negotiation outcome. From this study, following results were identified; i) situational constraints of negotiation effects on negotiation outcomes ii) arbitrary and continuous situations affect significantly positive on negotiation outcomes iii) submissive situations affect significantly negative effects on negotiation outcomes In conclusion, participant of negotiation and their managers try to promote negotiation situation toward to arbitrary and continuous situations if they have any availability.

• Journal of the Korean Data and Information Science Society
• /
• v.12 no.1
• /
• pp.27-40
• /
• 2001

The purpose of this study is to test a multiple change point in the regression model with the passage of time, using the estimated residual variance figure suggested by Gasser, Sroka and Jennen - Steinmez (GSJS). As a result of the simulation, it is showed that there is a jump change of the estimated residual variance figure at that time of change point. The way to analyse a intuitive multiple change point through graphics is more effective and accurate than any other existing ways.