• The Journal of the Korea Contents Association
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• v.13 no.11
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• pp.913-923
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• 2013

The purpose of this study was to provide a basis for the efficient and systematic management of the school physical education classes and to investigate the influence of sports club participation in school physical education classes. Three male and female middle school students by taking advantage of the simple random sampling method based on the D Metropolitan final 438 were selected for the study. The collected data, exploratory factor analysis, analysis of variance, correlation analysis, regression analysis was performed using the SPSS 20.0 program. The differences were most similar to the sports clubs and school physical education classes, according to the characteristics of personal satisfaction. The sports club activities, was affecting school physical education classes.

• Journal of the Korea Convergence Society
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• v.8 no.3
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• pp.253-263
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• 2017

It was conducted that yoga practice for the visually impaired Elderly has an influence on boby composition, flexibility and depression disease. Also, It has a purpose to provide a method of movement and basic materials for them. The 18 seventy-year-old men or women without any experience of yoga from the visually impaired association of the elderly in G city were participated in a training yoga session. This experiment was performed by simple random sampling with the nine of treat group (yoga training) and the nine of control group. The data was analyzed by covariance analysis with 0.05 significant level. The treat group were conducted twice a week to exercise (60mins) for twelve weeks. In conclusion, it is proved that yoga exercise has a positive effect on body composition, flexibility and depression disease.

• Journal of Advanced Navigation Technology
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• v.23 no.1
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• pp.20-35
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• 2019

In this article, we verified to influence on the performance through performance management system and public enterprise management evaluation implementation degree by the airport policy and leadership. Data collected from 533 employees of Incheon International Airport Corporation and Korea Airports Corporation. Sample extracted with a simple random sampling. Data analysis adopted structural equation modeling. The results of this research found that airport policy and leadership are the key variables influencing airport performance. This research verified a significant mediation effect on the public enterprise management evaluation implementation degree. Thus, this research assert that positive proposals for airport policy and insightful leadership must be taken. This paper explores new view in the public enterprise management evaluation research and offers practical help to researchers and practitioners in providing a direction for airport performance.

• Journal of Advanced Navigation Technology
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• v.26 no.5
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• pp.289-303
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• 2022

The purpose of this study verify to influence the effect of the 4th industrial revolution recognized by airport operators on the airport management system and the moderator effects of convergence and leadership between these influence relationships. Data collected through a survey of airport operators using simple random sampling at six international airports in Korea. Data analysis performed using Structural Equation Modeling. The research results found that the 4th industrial revolution had a positive effect on the airport management system. Also, moderator effects of convergence and leadership found significant statistically. In this paper, we asserts that it should be reconstructed the airport management system as a system suitable for the era of the 4th industrial revolution. This paper provide theoretical data and directions for empirical research to airport researchers, and implications for airport enterprise managers and airport policy planners. The findings of this study are particularly helpful for international airports that have adopted the technologies of the Fourth Industrial Revolution.

• Korean Journal of Weed Science
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• v.14 no.3
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• pp.163-170
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• 1994

The experiment was conducted in 1993 to find out a simple prediction method of weeds and to make the prediction models of weeds in paddy fields. The annuals producing fine seeds were apt to emerge at sampling soil only, on the contrary the perennials and the annuals producing large seeds tended not to emerge at sampling soil due to the miss of seeds at sampling. There was no appropriate regression between a total number of weeds emerged at sampling soil and that of weeds occurred in fields. The important annual weeds occurring in fields were able to predict by the number of weeds emerged at sampling soil, but it was difficult to predict the important perennial weeds. In case of Bidens tripartita producing large seeds and Eleocharis kuroguwai producing large tubers, the prediction coefficients were high as above 1.0, and that of Echinochloa crus-galli and Sagittaria pygmaea were comparatively high as 0.175 and 0.172, respectively. However the coefficients of the other weeds were much low as below 0.08. The prediction models for 9 species were made. The model of six species including E. crus-galli, M. vaginalis, R. indica, B. tripartita, E. triandra and S. pygmaea were linear regression with high significance, however that of 3 species including C. difformis, S. juncoides and E. kuroguwai were curve regression with high significance.

• Wind and Structures
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• v.4 no.5
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• pp.413-440
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• 2001

This paper presents an extensive analysis of unsteady wind loading data on a 18 m long and 2 m high wall in a rural environment, with the wind at a range of angles to the wall normal. The data is firstly analyzed using standard statistical techniques (moments of probability distributions, auto- and cross-correlations, auto- and cross-spectra etc.). The analysis is taken further using a variety of less conventional methods - conditional sampling, proper orthogonal decomposition and wavelet analysis. It is shown that, even though the geometry is simple, the nature of the unsteady flow is surprisingly complex. The fluctuating pressures on the front face of the wall are to a great extent caused by the turbulent fluctuations in the upstream flow, and reflect the oncoming flow structures. The results further suggest that there are distinct structures in the oncoming flow with a variety of scales, and that the second order quasi-steady approach can predict the pressure fluctuations quite well. The fluctuating pressures on the rear face are also influenced by the fluctuations in the oncoming turbulence, but also by unsteady fluctuations due to wake unsteadiness. These fluctuations have a greater temporal and spatial coherence than on the front face and the quasi-steady method over-predicts the extent of these fluctuations. Finally the results are used to check some assumptions made in the current UK wind loading code of practice.

• Journal of Institute of Control, Robotics and Systems
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• v.12 no.4
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• pp.346-352
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• 2006

In a networked control system (NCS), time delays which are larger than one sampling period can change the control period. As a result, it may cause system instability. This paper presents a control method for an NCS using the controller area network (CAN), where time delays arise in the control loop. Specifically, a simple yet efficient method is proposed to improve control performance in the presence of time delays. The proposed method, which can be regarded as a gain scheduling method, selects a suitable LQ control gain among several gains to deal with the problems due to the change of control period. It is found that the gain can be scheduled in terms of the relation between the gain and the sampling period, which is represented by first-order algebraic equations. The proposed method is evaluated with an inverted cart pendulum system where the actuator and sensors are connected through the CAN. Experiment results are presented to show the efficiency of the proposed method.

• The Journal of Asian Finance, Economics and Business
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• v.7 no.6
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• pp.427-437
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• 2020

This study seeks to examine empirically the effect of leadership style on organizational commitment and organizational effectiveness. The data are from all departments of the undergraduate program at the State University in Central Java, Indonesia. The study comprises all divisions of the undergraduate program, which amounted to 207 people. The method for sampling is based on simple random sampling. Structural equation modeling (SEM) is applied in order to analyze the data. The results show that integrative adaptive leadership style has a positive effect on teamwork and affective commitment. Therefore, in order to improve teamwork, the organization should be assisted in completing the introduction of collaborative conflict resolution. Moreover, affective commitment positively affects organizational effectiveness. Thus, it can be said that efforts to improve the organizational effectiveness, should be supported by affective commitment. The study further revealed that integrative adaptive leadership style has a positive effect on teamwork. This means better execution of integrative adaptive leadership, higher level of coordination and vice versa. Each member has different responsibilities and duties, and it can be done or resolved in different ways. If the leader can accommodate the creativity of the faculty and staff, a solid team can be formed.

• Journal of the Korean Society for Precision Engineering
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• v.17 no.12
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• pp.61-67
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• 2000

In switched reluctance motor(SRM) drive, it is necessary to synchronize the stator phase excitation with the rotor position. Therefore the rotor position information is an essential. Usually optical encoders or resolvers are used to provide the rotor position information. These sensors are expensive and are not suitable for high speed operation. In general, the accuracy of the switching angle is dependent upon the resolution of the encoder and the sampling period of the microprocessor. But the region of high speed, switching angles are fluctuated back and forth from the preset values, which are cause by the sampling period of the microprocessor. Therefore, the low cost linear encoder suitable for the practical and stable SRM drive is proposed and the control algorithm to provide the switching signals using the simple digital logic circuit is also presented in this paper. It is verified from the experiments that the proposed encoder and logic controller can be a powerful candidate for the practical low cost SRM drive.

• Communications for Statistical Applications and Methods
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• v.19 no.1
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• pp.23-32
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• 2012

This paper deals with the bias and variance of regression coefficient estimators in a finite population. We derive approximate formulas for the bias, variance and mean square error of two estimators when we select a fixed-size inclusion probability proportional to the size sample and then estimate regression coefficients by the ordinary least square estimator as well as the weighted least square estimator based on the selected sample data. Necessary and sufficient conditions for the comparison of the two estimators in terms of variance and mean square error are suggested. In addition, a simple example is introduced to numerically compare the variance and mean square error of the two estimators.