• The Mathematical Education
• /
• v.45 no.4 s.115
• /
• pp.481-491
• /
• 2006

Diffy is a simple mathematical puzzle that provides elementary-school students with subtraction practice. The idea appears to have originated in the late nineteenth century with E. Ducci of Itali. Thirty years ago Professor J. Copley of the University of Houston introduced the diffy game to teachers in elementary schools and it widely spreaded out. During the diffy activity we naturally guess many interesting conjectures. First, does diffy always end? Second, does the head of diffy always exist? Third, for an arbitrary given natural number n, is there any possible method to find the diffy with the given length n? In this study I give the necessary and sufficient condition for the existence of the head of diffy. Using this condition I classify all possible heads of diffy and provide an algorithm to find the diffy with any given length n. With this algorithm I find four natural numbers with diffy length 200. To ensure my numbers are correct, I make a diffy program for Mathematica and check they are correct. I suggest the diffy game is good for enlarging the mathematical thinking to all graded students, especially gifted and talented students, It will produce rational consideration and synthetic judgement.

• Journal of information and communication convergence engineering
• /
• v.8 no.1
• /
• pp.40-44
• /
• 2010

opportunistic spectrum access (OSA) allows unlicensed users to share licensed spectrum in space and time with no or little interference to primary users, with bring new research challenges in MAC design. We propose a cognitive MAC protocol using statistical channel information and selecting appropriate idle channel for transmission. The protocol based on the CSMA/CA, exploits statistics of spectrum usage for decision making on channel access. Idle channel availability, spectrum hole sufficiency and available channel condition will be included in algorithm statistical information. The model include the control channel and data channel, the transmitter negotiates with receiver on transmission parameters through control channel, statistical decision results (successful rate of transmission) from exchanged transmission parameters of control channel should pass the threshold and decide the data transmission with spectrum hole on data channel. A dynamical sensing range as a important parameter introduced to maintain the our protocol performance. The proposed protocol's simulation will show that proposed protocol does improve the throughput performance via traditional opportunistic spectrum access MAC protocol.

• Journal of the Korean Society of Manufacturing Technology Engineers
• /
• v.26 no.4
• /
• pp.351-356
• /
• 2017

The resistance of printed patterns for electrodes fabricated using printing technology should be minimized. This parameter depends on the pattern width and thickness; however, from the viewpoint of printability, the printed patterns should be printed at the designed width. The resistance of the printed patterns as well as printability is affected by various printing conditions. In this paper, the printing condition is optimized to minimize the resistance of electrodes printed by the roll-to-roll gravure method. This is done by considering the spread ratio of pattern width as a parameter of printability using design experiments. The drying temperature, dryer fan speed, and printing speed are selected as effective factors for the experiment objective. The optimized conditions are obtained and reproducibility test using these demonstrates that the optimized conditions can produce low-resistance electrodes for printability of the pattern width.

• Journal of Families and Better Life
• /
• v.31 no.5
• /
• pp.65-77
• /
• 2013

This study was aimed at (1) investigating expectant mothers' prenatal attachment according to variables (age, gestational weeks, perceived health condition, anticipating the gender of the fetus, marriage duration, and parity), (2) analyzing correlations among their prenatal attachment, spousal support, and parenting efficacy, and (3) examining the role of prenatal attachment as a mediator between spousal support and parenting efficacy. For this purpose, 221 expectant mothers living in Seoul completed a 55-item survey. The collected data were analyzed by t-test, one-way ANOVA, Pearson's correlation coefficients, and regression analyses. The findings of this study were as follows. First, among the variables, gestational weeks, perceived health condition, marriage duration, and parity showed significant differences in the scores for the overall prenatal attachment and subordinate factors. Second, there were positive correlations between the expectant mothers' prenatal attachment and spousal support and between their prenatal attachment and parenting efficacy. Third, the expectant mothers' prenatal attachment proved to mediate between spousal support and parenting efficacy. These findings shed light on the significance of prenatal attachment and spousal support during the pregnancy period; therefore, it is essential to develop education programs for expecting parents to enhance prenatal attachment and spousal support and to conduct follow-up studies to verify the effectiveness of the programs.

• The Korean Journal of Community Living Science
• /
• v.18 no.2
• /
• pp.313-321
• /
• 2007

The study examined the level of understanding and satisfaction of parents who should receive the food materials and monitor the food service, and would provided the basic data for more desirable school feeding system. The analysis was based on the participation level in materials receiving and food service monitoring, condition of equipment, knowledge about materials and the opinions about monitoring education. 160 monitors out of Daejeon primary schools were used and 60% of them were in the age of thirties and the others were in forties. Equipment condition for material receiving was good and most of the monitors were familiar with the ways of using the machines. Difficulties of material receiving were found in meat(65.6%) and sea food(21.9%), and the ratios of activities and the intention to participate in monitoring education were high with 25.0% and 72.5% respectively. Most of the monitors thought sanitary conditions of food materials(100.0%) and delivery persons(96.9%) were very good or good. And 90% of the respondents changed their perception of school food service positive after monitoring. In conclusion, most of the parents wanted to participate in the monitoring and material receiving actively and showed great willingness to receive monitoring education.

• English Language & Literature Teaching
• /
• v.17 no.4
• /
• pp.123-139
• /
• 2011

The purpose of the current study is to analyze a model of OPIc-based speaking test for Korea English classroom. The research questions were (1). What is the English teachers' opinion on the current speaking teaching and testing? (2). Is the OPIc speaking test appropriate in the Korea English class? and (3). What are the English education students' perceptions of the OPIc-based speaking test for English classes? To answer the first research question, a survey was conducted targeting one hundred and forty-seven teachers. The result of the survey shows that Korea English teachers' great concern on the English teaching and speaking test are "communicative competence," "scoring and criteria," and "condition and need." To answer the second research question, the OPIc speaking test for the class was analyzed and it was found that in terms of the communicative competence," "scoring and criteria," and "condition and need" issues, OPIc based speaking test is appropriate in Korea English class. For the third research question, Q methodology was used targeting English education students and the result shows that most English education students strongly agree to the statements that the OPIc-based speaking test has the advantage to improve communicative competence. This study may provide the information about creating and adopting tests for English classes and relating standardized test and the English classes.

• School Mathematics
• /
• v.12 no.3
• /
• pp.301-322
• /
• 2010

In this study, researchers developed the criteria evaluating mathematically gifted students' creative products, which contain such evaluation headings as cognitive abilities(; creativity, analytic thinking, expert skill and knowledge), performing ability of the Mathematically Gifted-Creative Problem Solving process. And then a case study is carried out to apply the criteria to an actual condition of mathematically gifted education. This case study shows that how teachers can apply those of model and criteria in actual condition of the mathematically gifted education. Through the criteria above mentioned, the characteristics of creative productivity can be grasped clearly and evaluated in detail.

• The Journal of Korean Society for School & Community Health Education
• /
• v.17 no.3
• /
• pp.117-129
• /
• 2016

Objectives: This study aimed to provide the high-quality clinical practice environment education to students by researching the social support, major satisfaction, and interpersonal ability of dental hygiene students, analyzing factors having influence on the clinical practice satisfaction, and then increasing the satisfaction with clinical practice. Methods: 312 students who have completed clinical practice among dental hygiene major of three colleges in Gyeonggi province were collected by convenience sampling from April 18th to April 27th 2016. Using SPSS 20.0, descriptive analysis, t-test, ANOVA, correlation analysis, and regression analysis were conducted. Results: The clinical practice satisfaction was correlated with interpersonal ability(r=0.383, p<.001), social support(r=0.239, p<0.01), subjective health condition(r=0.226, p<0.01), and major satisfaction(r=0.287, p<0.01). When interpersonal ability and social support were high, subjective health condition was good, and major satisfaction was high, the clinical practice satisfaction was also high. Conclusions: Based on the results, it would be necessary to develop operational reinforcing social support and interpersonal ability of dental hygiene students, and also to make efforts to increase the clinical practice satisfaction of dental hygiene students by establishing measures to increase their major satisfaction.

• Journal of Engineering Education Research
• /
• v.12 no.1
• /
• pp.42-56
• /
• 2009

This study derives the suggestions for promotion of internationalization of universities. The reasons for increase in number of international students were analyzed and present condition of international students has been investigated. Research and analysis of International students support program of government was performed. Moreover, the questionnaire was Prepared based on literature review of national and international policies for the support on international students and the survey was conducted on international students studying in engineering programs at graduate level. Finally, suggestions for government, university and education institutions have been made for the improvement of international student support programs to promote internationalization of universities.

• Journal of the Korean Society of Earth Science Education
• /
• v.7 no.2
• /
• pp.151-158
• /
• 2014

This study was designed to analyze fifty-seven high school students' perception of environmental change through drawing. More than half of the students showed the present environment as a pure natural space, and they represented the future environment as a space which includes the artificial contents, they also expressed technology advance in their picture. Most of high school students showed the negative perception to express the present environmental condition in a polluted space by human. In matters of the future environmental condition, half of students expressed it positively, the other half of students expressed it negatively, we should develop our will to improve the environment, and try to change student's preception positively.