• Journal of Mechanical Science and Technology
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• v.15 no.12
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• pp.1829-1834
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• 2001

The choking of dual subsonic streams flowing through a convergent duct in contact has been investigated experimentally and theoretically. The experiment was conducted by using blow-down wind tunnel. The condition, when the dual stream flow chocking (compound choking) occurs at the nozzle exit, was explained by one-dimensional analysis of compound sound wave propagation. The experimental results for the condition of compound choking were compared with the prediction from theoretical analysis, and the schlieren optical method using the spark light source has been used to visualize the flowfield.

• Journal of Information Technology Application
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• v.3 no.1
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• pp.91-108
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• 2001

Participatory Design (PD) community recognized that identification of use case scenarios describing possible uses of the future system is beneficial for users to identify their system requirements. However, brainstorming is a typical methodology for users to create use case scenarios during PD session, which heavily depend on the people skill and experiences of the analysts. The objective of this study is to develop a theoretical framework for automatic generation of requirement scenarios. Automatically generated scenarios serves as a menu of the possible user requirements from which user group can start to generate ideas about their requirements. The convergent approach taken here is novel in that the generated scenarios describe system requirements as well as the business process requirements in which the system operates. A context-sensitive grammar is used to generate the context relevant requirement scenarios.

• Structural Engineering and Mechanics
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• v.9 no.2
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• pp.153-168
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• 2000

This paper presents four incompatible but convergent Rational quadrilateral elements, two four-node elements (RQ4Z and RQ4B) and two five-node elements (RQ5Z and RQ5B). The difference between the so-called Rational Finite Element (Zhong and Zeng 1996) and the Free Formulation (Bergan and Nygard 1984) are discussed and compared. The importance of the mode completeness in these formulations is emphasized. Numerical results for several benchmark problems show the good performance of these elements. The two five-nodes elements RQ5Z and RQ5B, which can be viewed as complete quadratic mode elements (with seven stress modes), always give better results than the four nodes elements RQ4Z and RQ4B.

• Journal of Institute of Control, Robotics and Systems
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• v.16 no.11
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• pp.1025-1028
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• 2010

This paper presents a new approach to analyze the stability of dynamic competitive markets within the framework of supervisory control of discrete event systems. A competitive market is representative of free market economy where it is well known that an invisible hand (also referred to as Walrasian auctioneer) always achieves an equilibrium of demand and supply. Upon the framework of supervisory control theory, this paper shows that Walrasian auctioneer is a stabilizing supervisor for a convergent competitive market, however a non-convergent competitive market (e.g. a free market under economic bubble and depression) controlled by Walrasian auctioneer may not be stable.

• Journal of the Korea Society of Computer and Information
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• v.22 no.8
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• pp.93-100
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• 2017

After the fourth industrial revolution came along, SW education to improve creativity and problem-solving ability began in elementary, middle, and high schools first and then in universities as well positively; however, research on the curriculum or what it has to pursue is not yet enough. Here, this study will investigate the current status of SW education provided in software-oriented schools operated in universities and also given as cultural studies in general universities and examines the curriculum or the standard plan for education. In most schools, it is operated as similar subject names, and diverse methods are tried on- and off-line to cultivate computing thinking skills. Also, to study SW education programs that can be operated in the general cultural courses of universities and find out how to utilize them, this author suggests the goal setting, educational contents, and teaching methods for SW education. As follow-up tasks, it will be needed to apply the suggested programs to the field and find out new evaluation methods in order to cultivate creative and convergent persons of ability.

• Korean Journal of Child Studies
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• v.20 no.2
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• pp.225-242
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• 1999

The psychometric properties of a preliminary version of the Friendship Quality Scale(FQS) were examined with data collected from 300 3rd and 5th grade children. Scores on the Self-Perception Scale were obtained to examine convergent validity. The FQS assesses friendship quality in 9 sub-scales, inclusive of 6 friendship functions. Factor analysis confirmed the 9 sudscale structure of the FQS for 5th graders, but 4 friendship functions instead of 6 were a better fit for 3rd graders. Except for one, the sub-scales showed relatively high internal consistency ; Cronbach ${\alpha}$ ranged from .70 to .93. Convergent validity was indicated by correlations between self-perception and sex differences in friendship functions. Friendship functions and satisfaction were related to self-perceptions in social acceptance, behavior, and global self-worth. Girls reported higher friendship functions and satisfaction in friendship than boys.

• Korean Journal of Child Studies
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• v.28 no.5
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• pp.55-72
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• 2007

Replication of the factor structure of the TBAQ(Toddler Behavior Assessment Questionnaire Goldsmith, 1988) in Korean 2-year-old children was examined by Multitrait Multimethod matrix of observed and reported child behavior. Participants included 113 toddlers and their mothers. Three factors comprising 63 items were identified and labeled as easy, difficult and fearful. On the Child Behavior Checklist(Achenbach & Edelbrock, 1983) difficult temperament was positively related to externalizing while fearful temperament was positively related to internalizing problems. Observation of inhibited child behavior in both unfamiliar social and nonsocial situations demonstrated a positive relationship to observed inhibition of fearful temperament. Easy temperament correlated negatively with both social inhibition and internal behavior problems. Results supported construct validity of TBAQ factors for Korean 2-year-old children.

• Journal of the Korean Institute of Intelligent Systems
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• v.8 no.3
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• pp.71-79
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• 1998

This paper introduces a new optimization algorithm which is combined with genetic algorithm and random tabu search method. Genetic algorithm is a random search algorithm which can find the global optimum without converging local optimum. And tabu search method is a very fast search method in convergent speed. The optimizing ability and convergent characteristics of a new combined optimization algorithm is identified by using a test function which have many local optimums and an optimum allocation of pipe support. The caculation results are compared with the existing genetic algorithm.

• Journal of Power System Engineering
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• v.18 no.3
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• pp.66-72
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• 2014

The local heat transfer and pressure drop of developed turbulent flows in the smooth convergent/divergent channels with rectangular and square cross-sectional areas along the axial distance have been investigated experimentally. The measurement was conducted within the range of Reynolds numbers from 15,000 to 89,000. The channel hydraulic diameter ratios of 0.67 and 1.49 in the rectangular channel with 2 inclined walls and the ratios 0.75 and 1.33 in the square channel with 4 inclined walls are considered. The comparison showed that among the four channels the square divergent channel has the highest thermal performance at the identical mass flow rate, at the identical pumping power, and at the static pressure drop.

• Kyungpook Mathematical Journal
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• v.55 no.2
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• pp.355-372
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• 2015

In the present paper, by using the Fibonacci difference matrix, we introduce the almost convergent sequence space $\hat{c}^f$. Also, we show that the spaces $\hat{c}^f$and $\hat{c}$ are linearly isomorphic. Further, we determine the ${\beta}$-dual of the space $\hat{c}^f$ and characterize some matrix classses on this space. Finally, Fibonacci core of a complex-valued sequence has been introduced, and we prove some inclusion theorems related to this new type of core.