• Journal of Educational Research in Mathematics
• /
• v.12 no.1
• /
• pp.71-79
• /
• 2002

Visualization have strong driving force that enables us to recognize abstract mathematics by direct and specific method in school mathematics. Specially, visual thinking helps in effective problem solution via intuition in mathematics education. So, this paper examines the meaning of visualization, the role of visualization in intuitive problem solving process and the methods for enhancement of intuition using visualization in mathematics education. Visualization is an useful tool for illuminating of intuition in mathematics problem solving. It means that visualization makes us understand easily mathematical concepts, principles and rules in students' cognitive structure. And it makes us experience revelation of anticipatory intuition which finds clues and strategy in problem solving. But, we must know that visualization can have side effect in mathematics learning. So, we have to search for the methods of teaching and learning which can increase students' comprehension about mathematics through visualization and minimize side aspect through visualization.

• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.11 no.9
• /
• pp.431-438
• /
• 2001

This paper present experimental results of source identification for non-minimum phase system. Generally, a causal linear system may be described by matrix form. The inverse problem is considered as a matrix inversion. Direct inverse method can\`t be applied for a non-minimum phase system, the reason is that the system has ill-conditioning. Therefore, in this study to execute an effective inversion, SVD inverse technique is introduced. In a Non-minimum phase system, its system matrix may be singular or near-singular and has one more very small singular values. These very small singular values have information about a phase of the system and ill-conditioning. Using this property we could solve the ill-conditioned problem of the system and then verified it for the practical system(cantilever beam). The experimental results show that SVD inverse technique works well for non-minimum phase system.

• Research in Community and Public Health Nursing
• /
• v.29 no.1
• /
• pp.97-107
• /
• 2018

Purpose: A mediated model of Korean college students' problem gambling based on Blaszczynski and Nower's pathway model is developed and tested to explore mediating roles of self-control and irrational gambling beliefs in the association between emotionally vulnerable variables and problem gambling. Methods: 273 student participants recruited from 4 universities in Seoul and Gyeonggi, Korea responded. Data were collected with a structured self-report questionnaire comprising measures of problem gambling, depression, anxiety, coping styles, irrational gambling belief, and self-control. Results: The modified research model provides a reasonable fit to the data. Depression, anxiety, reflective coping, irrational beliefs, and self-control turned out to have direct effects on problem gambling, while indirect effects were reported in some suppressive and reactive styles. These predictors account for 38% of the college students' problem gambling. Conclusion: The findings suggest that developing intervention programs for reducing depression, anxiety, irrational gambling beliefs, and increasing reflective coping and self-control are needed to prevent Korean college students'problem gambling.

• Korean Journal of Child Studies
• /
• v.33 no.2
• /
• pp.185-201
• /
• 2012

The purpose of the present study was to investigate the structural relationships between adolescent problem behaviors and related variables. The subjects of this study consisted of 250 to second graders from a middle school in S city in the Gyeongbuk province of South Korea. The sample variance-covariance matrix was analyzed using AMOS 20.0, and a maximum likelihood minimization function. The results were as follows : First, marital conflict in terms of the father's open communication model indicated both a direct and indirect effect upon adolescent problem behaviors. Marital conflict in terms of the father's problematic communication model revealed an indirect effect upon adolescent problem behaviors also indicated that these behaviors were also mediated by the father's problems communication. Second, a open communication style on the part of the father indicated a partially mediating effect on the relationship between marital conflict and adolescent problem behaviors. The problematic communication model on the part of the father revealed a very clear mediating effect on the relationship between marital conflict and adolescent problem behaviors.

• Korean Journal of Human Ecology
• /
• v.24 no.6
• /
• pp.783-793
• /
• 2015

The purpose of this study was to investigate the effect of Parenting Attitude, Self-esteem, and Peer Attachment on Emotion Problem. The study is based on data from first wave of 'Korean Child Youth Panel Survey 2010(KCYPS)' and the subjects of this survey were 2,098 1st grade junior middle school students. To measure the variables, this study used such scales as the parenting attitude scale, self-esteem scale, and peer attachment scale and emotional problem scale. The data were analyzed using descriptive statistics, Pearson's correlation and structural equation modeling analysis. Results of structural equation modeling with data indicated that hypothesized structural equation model produced a good fit but, no direct effect between negative parenting attitude and peer attachment. The self-esteem have mediating effect between parenting attitude and peer attachment, emotion problem. The peer attachment have mediating effect between positive parenting attitude and emotion problem but, did not have mediating effect between negative parenting attitude and emotion problem. The implications for counseling and suggestions for future research are discussed.

• Journal of Engineering Education Research
• /
• v.22 no.3
• /
• pp.32-40
• /
• 2019

This paper deals with the effects of teamwork competence on problem solving ability through the mediating effect of creative personality for the engineering students. For this purpose, a regression-based statistical mediation analysis has been performed for a simple mediation model in which teamwork competence and problem solving ability were treated as independent and dependent variables respectively, and creative personality was included as a mediation variable. The analysis results showed that the teamwork competence has direct effect on the problem solving ability as well as indirect effect through the creative personality. This result implies that the problem solving ability can be improved directly by improving the teamwork competence, and moreover, it can be further improved indirectly or through the mediation effect by improving the creative personality. Thus, in order to develop excellent problem solving ability, it is necessary to form team members in a balanced way between teamwork competence and creative personality in the team-based learning.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.10 no.9
• /
• pp.2340-2349
• /
• 2009

In this paper we proposed a hopping routing scheme to resolve the hot spot problem for periodic monitoring services in wireless sensor networks. Our hopping routing scheme constructs load balanced routing path, where an amount of energy consumption of all nodes in the sensor networks is predictable. Load balanced routing paths can be obtained from horizontal hopping transmission scheme which balances the load of the sensor nodes in the same area, and also from vertical hopping transmission scheme which balances the load of the sensor nodes in the other area. The direct transmission count numbers as load balancing parameter for vertical hopping transmission are derived using the energy consumption model of the sensor nodes. The experimental results show that the proposed hopping scheme resolves the hot spot problem effectively. The efficiency of hopping routing scheme is also shown by comparison with other routing scheme such as multi-hop, direct transmission and clustering.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.41 no.5
• /
• pp.565-573
• /
• 2016

Wi-Fi Direct standard technology(Wi-Fi Peer to Peer Technical Specifications v1.2, 2010) was designed for allowing peer to peer communication between two or more devices and various products which have been currently manufactured such as smart phone and smart TV have already provided this technical function. In this technology the role of Coordinator in Wi-Fi infrastructure would be matched to GO(Group Owner) which needs relatively high energy resource and computation power due to the high probability for allowing 3rd-party connection, however, the current standard specification would be limited in terms of energy distribution because it has not included a process to determine the role of GO. To address above problem, this paper classified considerable parameters into the general parameters for the physicality of devices and the specific parameters for considering the role position depending on use-case scenario, and proposed a new method called DIVA to help efficiently determining GO role from the member devices of Wi-Fi Direct network. Furthermore the effect of this mechanism was proved via simulation-based experiments.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.41 no.6
• /
• pp.631-639
• /
• 2016

Wi-Fi Direct standard technology has been widely deployed on the recently manufactured products such as smart phone, smart monitor, TV, set-top box, and gaming console, and it was published from Wi-Fi Alliance with the name of Wi-Fi Peer-to-Peer Technical Specifications (v1.4, 2014) for direct connection on the wireless communication environment. However, the connection process of this standard needs 5 to 10 seconds so it can lead to user's inconvenience as well as long delay for connection. From the focus of that this problem was derived from long discovery process composed of Scan and Find, as a result, the proposed scheme on this paper modified and adapted Scan and Find processes with reassembling steps of them for reducing the connection delay. In addition, the analysis and experiments were progressed for the evaluations of the proposed scheme.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.45 no.4
• /
• pp.232-236
• /
• 2000

To obtain a basic information on the development of effective control strategies for weedy rice in direct seeding rice cultivation, occurrence patterns of weedy rice as influenced by different cultural practices such as cultivation method, water management, seeding time, and tillage were investigated in field or pot experiments. High occurrence of weedy rice was observed in a continuous direct seeding paddy field as compared to machine transplanted one. Based on the percent of weedy rice panicle over three years trial, high ridged dry seeding was highest with 36.9%, followed by wet seeding with 30.9%, water seeding with 14.6% and machine transplanting rice with 0.8%, indicating 97.8% reduction in weedy rice occurrence by machine transplanting rice as compared with high ridged dry seeding. Germination of weedy rice was promoted to 83-94 % when rice panicle was flooded from September 30 to October 10 for 6 days and 74-88% for 9 days on October 20. Weedy rice occurrence was also substantially reduced by delayed seeding on June 10 and intensive tillage. The results suggest that machine transplanting rice be more effective cultural practice than flooding treatment, delayed seeding and intensive tillage when weedy rice problem occurs in direct seeded paddy field.