• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.9 no.6
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• pp.29-35
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• 2009

An efficient stochastic channel selection algorithm for cognitive radio networks is proposed and analyzed in this paper. With the new algorithm utilizing quality of channels, the stationary level of the channels in idle state and history performance, we can find the best channel for secondary users to transmit data. Moreover, this method not only restricts channel switching of secondary users but also adapts to random resource environment of cognitive radio network. The advantages of the proposed algorithm are demonstrated clearly through computer simulation.

• Journal of the Korean Institute of Educational Facilities
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• v.1 no.1
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• pp.49-61
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• 1994

This study aims to indicate fundamental problems and also to supply basic data for the reasonable distribution of the educational facilities in an effort to build better educational environments by examining and analyzing their changing process in primary and secondary schools in accordance with the changes in school year system in the period between 1900 to 1993. The following conclusion can be drawn : a. Separation of Middle and high schools due to the change of the school year system in 1951 into 6 - 3 - 3 - 4, has had great influence upon the arrangement of the educational facilities. b. Educational facilities in primary and secondary school are expanding, but they do not meet the criterion on an appropriate scale. Especially educational facilities of high schools need to be extended.

• 한국전산유체공학회:학술대회논문집
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• 2007.10a
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• pp.134-140
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• 2007

Nonlinear parabolized stability equations for compressible flow in general curvilinear coordinate system are derived to deal with a broad range of transition prediction problems on complex geometry. A highly accurate finite difference PSE code has been developed using an implicit marching procedure. Blasius flow is tested. The results of the present computation show good agreement with DNS data. Nonlinear interaction can make the T-S fundamental wave more unstable and the onset of its amplitude decay is shifted downstream relative to linear case. For nonlinear calculations, rather small difference in initial amplitude can produce large change during nonlinear region. Compressible secondary instability at Mach number 1.6 is also simulated and showed that 1.1% initial amplitude for primary mode is enough to trigger the secondary growth.

• Journal of Food Hygiene and Safety
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• v.9 no.1
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• pp.43-48
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• 1994

Instrumental determination was performed for the analysis of residues of ethylene oxide(EO), ethylene chlorohydrin(ECH) and ethylene glycol(EG) in white ginseng powders which were deaerated for 30 min after EO fumigation. Gas chromatographic data showed that EO residues were 570 ppm in the immediate samples after deaeration and 170 ppm in the stored ones for 8 days at 30$\pm$1$^{\circ}C$, respectively, showing a decreasing tendency with elapsed time. On the other hand, ECH and EG residues in samples as the secondary products of EO were 17, 650 ppm and 727 ppm stored for one month, and 9, 595 ppm and 221 ppm stored for 3 months, respectively.

• Journal of Korean Home Economics Education Association
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• v.7 no.1
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• pp.81-95
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• 1995

The purpose of the study were to :(1)determine important home management concepts in the secondary home economics education curriculum, (2) identify the educational needs related to home management perceived by home economics teachers, and the factors affecting it. (3) use the findings to make recommendations for developing home economics curriculum and teaching home economics in the secondary school. The questionnaires were distributed to the 385 home economics teachers, lived in seoul, local cities and rural area. The data were analyzed by using descriptive statistics, t-test one way ANOVA with scheffe test, factor analysis, and multiple regression analysis. Forty home management concepts were selected based on the related literatures. Resource use, environmental concerns, consumer rights and consumer problems were the concepts which showed the highest level of educational needs perceived by the teachers. The educational needs were affected by school level, residence area of the respondents, age, career, and other factors related to the perception about home management education.

• Proceedings of the KSME Conference
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• 2000.04b
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• pp.661-666
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• 2000

Near-wake flow field of a circular cylinder is studied by means of a cinematic PIV system with high sampling rate and large internal memory block. Experiments are conducted in a closed-cycle water tunnel system and a cross-correlation algorithm in conjunction with FFT (Fast Fourier Transform) analysis and an offset correlation technique is used for vector processing. With the help of very high sampling frequency compared to the shedding frequency, it is possible to obtain phase-averaged information of the three-dimensional wake, even though the shedding is not forced but natural. Phase-locked vortical structures observed simultaneously from the spanwise and cross-stream planes are displayed in the wake-transition regime where fine-scale secondary vortices have a spanwise wavelength or around one diameter. Spatial relations and temporal evolutions of the primary Karman vortex and the secondary vortex are also discussed schematically.

• The Journal of the Korea institute of electronic communication sciences
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• v.12 no.6
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• pp.1115-1120
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• 2017

In this paper, we apply the LMMSE(: Linear Minimum Mean Square Error) algorithm to overcome the Doppler effect according to the UAV(: Unmanned Aerial Vehicle) velocity in multipath fading channel environment. Simulation results show that the performance difference depends on the pilot arrangement and pattern, and we confirmed that the frame structure proposed in this paper can provide a stable secondary link for high speed UAV system.

• Journal of the Korean Home Economics Association
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• v.34 no.4
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• pp.175-186
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• 1996

The main purpose of this study is to provide basic data for the development of secondary Home Economics education curriculum and program by investigating the recognition perceived by Home Economics teachers. We have done statistical analyses of 237 questionnaires on the Home Economics teachers' recognition. The results are as follows: 1) The respondents evaluated the necessity of Home Economics education in secondary school, application of aquired knowledge and technical skill and learning by practical experience, highly. 2) As for the contents of Home Economics education curriculum, the respondents place a high value on the field of Meal Management, Child and Family Studies, Home resourse Management and Consumer life, Clothing Management, and House Planning and Management, in the order. 3) The most important educational concepts are knowledges and understanding for the human beings.

• Korean Journal of Health Education and Promotion
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• v.15 no.1
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• pp.165-178
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• 1998

The purpose of this explanatory study was to provide baseline information on the secondary prevention health behavior of cervical cancer in Korea which was related to the utilization of the Papanicolaou (Pap) smear screening test. The secondary data from the 1992 Korean Health Behavior Survey was used for analysis in order to determine sociodemographic profiles and the predictor variables. The sample analyzed for this study contained 1,489 Korean women residing in Korea aged 20-59 selected by multi-stage sampling method from the 1990 Korean census. Univariate, bivariate, and logistic regression analysis were performed to produce the findings of this study. Only 27.9% of the study sample had had a Pap test in 1992. It was found that the relative sociodemographic profiles of the Pap test between users and non-users were distinctive. The predictors variables were age, marital status, educational status, usual source of care, perceived household economic status, health check-up, and presence of chronic diseases

• Journal of Fisheries and Marine Sciences Education
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• v.21 no.3
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• pp.390-399
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• 2009

The present study investigated the differences in thinking styles and critical thinking dispositions between elementary school and secondary school pre-service teachers. For this research, 295 college students were selected. The subjects completed the Thinking Styles Inventory(TSI) and the California Critical Thinking Dispositions Inventory(CCTDI). Data were analyzed by descriptive statistics, and MANOVA. The results of this study were as follows: First, there were not statistically significant differences by group in the thinking styles(Type I and Type II). Second, there were statically significant differences according to group in the CCTDI. In this result, secondary school pre-service teachers had higher scores than female students in self-confidence sub-scale of CCTDI.