• Communications for Statistical Applications and Methods
• /
• v.19 no.3
• /
• pp.367-379
• /
• 2012

In baseball rankings, prediction has been a subject of interest for baseball fans. To predict these rankings, (based on 2011 data from Korea Professional Baseball records) the arithmetic mean method, the weighted average method, principal component analysis, and principal component regression analysis is presented. By standardizing the arithmetic average, the correlation coefficient using the weighted average method, using principal components analysis to predict rankings, the final model was selected as a principal component regression model. By practicing regression analysis with a reduced variable by principal component analysis, we propose a rank predictability model of a pitcher part, a batter part and a pitcher batter part. We can estimate a 2011 rank of pro-baseball by a predicted regression model. By principal component regression analysis, the pitcher part, the other part, the pitcher and the batter part of the ranking prediction model is proposed. The regression model predicts the rankings for 2012.

• Journal of Information Processing Systems
• /
• v.5 no.1
• /
• pp.5-10
• /
• 2009

Text data has always accounted for a major portion of the world's information. As the volume of information increases exponentially, the portion of text data also increases significantly. Text classification is therefore still an important area of research. LDA is an updated, probabilistic model which has been used in many applications in many other fields. As regards text data, LDA also has many applications, which has been applied various enhancements. However, it seems that no applications take care of the input for LDA. In this paper, we suggest a way to map the input space to a reduced space, which may avoid the unreliability, ambiguity and redundancy of individual terms as descriptors. The purpose of this paper is to show that LDA can be perfectly performed in a "clean and clear" space. Experiments are conducted on 20 News Groups data sets. The results show that the proposed method can boost the classification results when the appropriate choice of rank of the reduced space is determined.

• Journal of Korean Association for Spatial Structures
• /
• v.3 no.4 s.10
• /
• pp.77-84
• /
• 2003

Tensegrity systems are stable structures which are reticulated spatial structures composed of compressive straight members, struts and cables. But there are some difficulties concerning surface stability, surface formation and construction method. One of the ways to solve this problem reasonably is combination of tesile members and rigid members. This structure is a type of flexible strutural system which is unstable initially because the cable material has little initial rigidity. Therefore tensegrity structure need to be introduced to the Initial stress for the self-equilibrated system having stable state. The rigidification of tensegrity systems is related to selfstress states which can be achieved only when geometrical and mechanical requirements are simultaneously satisfied. In this paper, for the stabilization of tesnsegrity structure it is proposed the modified self-equilibrated equation and the range of the various geometrical parameter about unit system. And we generate the model of double layed single curvature arch using the new squew quadruplex unit system.

• Journal of the Korean Institute of Telematics and Electronics B
• /
• v.29B no.2
• /
• pp.18-26
• /
• 1992

MR(Model Reduction) is presented in order to estimate the frequency of multiple sinusoids from the finite noisy data with the white or colored noises. MR, using the reduced rank models, is designed, appling the approximation of linear system to LP(Linear Prediction). The MR method is analyzed. Monte-carlo simulations are conducted for MR and Lp. The results are compared with in terms of mean, root-mean square and relative bias. MR eliminates effectevely the extremeous and exceptional poles appearing in LP and improves the accuracy of LP. Especially, MR gives promising results in short noisy measurements, low SNR's and colored noises. Power spectral density and angular frequency position are showed by figures, for examples. Finally, the new method is utilized to the communication and biomedical systems estimating the characteristics of the signal and the system identification modelling the dynamic systems from experimental data.

• Journal of Korean Association for Spatial Structures
• /
• v.2 no.2 s.4
• /
• pp.69-76
• /
• 2002

The basic systems of spatial structures such as shells, membranes, cable-nets and tensegrity structures have been developed to create the large spaces without column. But there are some difficulties concerning structural stability, surface formation and construction method. Tensegrity systems are flexible structures which are reticulated spatial structures composed of compressive members and cables. The rigidification of tensegrity systems is related to selfstress states which can be achieved only when geometrical and mechanical requirements are simultaneously satisfied. In this paper, the force density method allowing form-finding for tensegrity systems is presented. And various modules of unit-structures are investigated and discussed using the force density method. Also, a model of double-layered single curvature arch with quadruplex using supplementary cable is presented.

• Communications for Statistical Applications and Methods
• /
• v.15 no.3
• /
• pp.411-420
• /
• 2008

This paper considers a feasible two-step estimator for seasonal cointegration as the extension of $Br{\ddot{u}}ggeman$ and $L{\ddot{u}}tkepohl$ (2005). It is shown that the reducedrank maximum likelihood(ML) estimator for seasonal cointegration can still produce occasional outliers as that for non-seasonal cointegration even though the sizes of them are not extreme as those in non-seasonal cointegration. The ML estimator(MLE) is compared with the two-step estimator in a small Monte Carlo simulation study and we find that the two-step estimator can be an attractive alternative to the MLE, especially, in a small sample.

• International Journal of Computer Science & Network Security
• /
• v.22 no.11
• /
• pp.184-188
• /
• 2022

The article considers the improved method and model of automated air situation assessment using a decision support system based on fuzzy networks of target installations. The advanced method of automated assessment of the air situation using the decision support system is based on the methodology of reflexive control of the first rank. With this approach, the process of assessing the air situation in the framework of the formulated task can be reduced to determining the purpose, probabilistic nature of actions and capabilities of the air target. The use of a homogeneous functional network for the formal presentation of air situation assessment processes will formally describe the process of determining classes of events during air situation assessment and the process of determining quantitative and qualitative characteristics of recognized air situation situations. To formalize the patterns of manifestation of the values of quantitative and symbolic information, it is proposed to use the mathematical apparatus of fuzzy sets.

• Asia-Pacific Journal of Business
• /
• v.15 no.3
• /
• pp.449-468
• /
• 2024

Purpose - The purpose of this study was to analyze the civil servant pension system in Korea, focusing on general administrative officials. Design/methodology/approach - This study developed a pension projection model that reflects the latest reforms and applied it to forecast the income replacement ratio and benefit ratios. Based on these projections, the study examined financial trends and proposed necessary reforms to ensure sustainability, such as adjusting the pension age. Findings - First, the benefit ratio decreases with later birth cohorts, showing that the reforms have reduced benefit gaps across generations. Second, while fairness within the same generation shows little difference between ranks, differences in income levels still result in significant disparities in pension amounts. Lastly, the pension deficit is expected to increase until 2029, after which it will gradually decrease, though further reforms are needed to ensure long-term financial sustainability. Research implications or Originality - This study is the first to comprehensively assess the fairness and sustainability of the civil servant pension system in Korea, considering both inter- and intra-generational equity. The findings provide valuable insights for policymakers aiming to ensure the system's sustainability as well as maintaining fairness across different cohorts and income levels.

• Journal of Korean Public Health Nursing
• /
• v.27 no.3
• /
• pp.619-632
• /
• 2013

Purpose: The purpose of this study was to develop an obesity management program for obese children and examine its effects on body composition, self-efficacy, and health promotion. The obesity management program was based on a KAP & HBM mixed model and consisted of health education and group playing exercises. Method: This study was implemented at one elementary school in K city for a total of 12 weeks. The study subjects were a single group, and their body composition, self-efficacy, and health promotion were assessed at both pre-treatment and post-treatment. Data were analyzed by Wilcoxon Signed Rank Test using SPSS WIN 20.0. Result: After the program, the average height of subjects increased by 0.9cm (p=.001), whereas BMI decreased by $0.64kg/m^2$ (p=.003), obesity index decreased by 3.79% (p=.003), and body fat decreased by 1.34% (p=.002). There were significant effects on diet self-efficacy (p=.027), exercise self-efficacy (p<.001), and health promotion (p=.001). Conclusion: This obesity management program reduced the degree of obesity and improved self-efficacy and health promotion. Therefore, the obesity management program is an effective intervention method for elementary-aged obese children.

• Korean Journal of Hospice Care
• /
• v.2 no.1
• /
• pp.21-40
• /
• 2002

Cancer is the second leading cause of the death in Korea. Family caregivers of dying patients manifest many psychological and physical symptoms of stress, and they often seek for informational support from health care providers. Unfortunately, however, few systematic studies identify the actual effect of such support on family caregivers. This study, thus, intends to evaluate the effect of informational support for hospice care. One group pretest-posttest design was used, employing the stress-coping model by Cohen and Wills as a conceptual framework. This research was conducted from July 1 to November 15, 1998, initially with 32 subjects sampled from hemato-oncology department of two general hospitals in Seoul, but reduced to 18 at the end due to the untimely death of patients or caregiver's refusal during the course of study. Informational supports were programmed to provide the family caregivers with 8 times of education and counseling as well as 24-hour hot-line for 4 weeks. A booklet that explains the various problems of hospice care was also prepared and distributed to all subjects. Data were collected by using self-report questionnaires and reviewing medical records. The tools used in this study were based on the Weinert's PRQ-II(scale of perceived social support), Spielberger's state anxiety inventory, and CES-D. Also included in the data collection were the general characteristics of family caregivers and patients, and the pain intensity and the performance status of patients. The data were analyzed with descriptive statistics, Wilcoxon sign rank test and paired t-test using SPSSWIN program. The results of the study were as follows: 1.The perceived social support of family caregivers was not significantly increased with informational support for hospice care(t=1.64, one tailed p=.060). 2.The anxiety of family caregivers was significantly reduced following informational support for hospice care(t=3.48, one tailed p=.002). 3.The depression of family caregivers was significantly reduced following informational support for hospice care(t=-2.18, one tailed=.022). 4.The pain intensity of patients with terminal cancer was significantly reduced following informational support for hospice care(t=-2.41, two tailed p=.027). The results suggest that the informational support provided to family caregivers of patients with terminal cancer reduced not only their anxiety and depression but also the pain intensity of patients. Further study is necessary to consolidate the conceptual framework of this study with expanded number of subjects. Nevertheless, it was certain that the informational support program for hospice care was very helpful to both caregivers and patients. Thus, the informational support program is strongly recommended for the hospitals which have no hospice unit yet.