• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.31 no.5
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• pp.335-340
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• 2018

Transition metal oxide materials have attracted widespread attention as Li-ion battery electrode materials owing to their high theoretical capacity and good Li storage capability, in addition to various nanostructured materials. Here, we fabricated a CoO Li-ion battery in which Co nanoparticles (NPs) are deposited into a current collector through electrophoretic deposition (EPD) without binding and conductive agents, enabling us to focus on the intrinsic electrochemical properties of CoO during the conversion reaction. Through optimized Co NP synthesis and electrophoretic deposition (EPD), CoO Li-ion battery with 630 mAh/g was fabricated with high cycle stability, which can potentially be used as a test platform for a fundamental understanding of conversion reaction.

• Proceedings of the KIEE Conference
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• 1997.07f
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• pp.2028-2032
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• 1997

When a high performance current control is desired, a computation time delay of a digital control system may deteriorate the control performance of a current controller. Such a non-negligible effect can be considerable in transient state. This paper deals with the modified predictive current control that compensates the time delay effects of a conventional predictive current control. The method is closely related to a local average current control and a symmetrical PWM pattern generation. Also some theoretical approaches are presented to describe the voltage saturation boundary of the power converter. For validation, the proposed method is applied to an active power filter system. The experimental results show considerable improvement in current tracking capability.

• Proceedings of the KIEE Conference
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• 1996.07a
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• pp.77-79
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• 1996

The model interrupters of $SF_6$ gas electromagnetic contactor whose ratings are 7.2kV, 4.0kA have been designed and manufactured on the basis of theoretical and computational analysis for its development. The eddy current analysis, the magnetic field analysis and the calculation of the rotational force on arcs have been conducted using FLUX2D package. The short circuit current interrupting tests have been conducted for the model interrupters using the simplified synthetic testing facility in KERI. The results show that the model interrupters have sufficient interrupting capability and the new design concept is prefer for good interrupting performance.

• Journal of Families and Better Life
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• v.10 no.1 s.19
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• pp.15-25
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• 1992

This article introduces the conceptual framework of self-efficacy and reviewes recent research articles which are related to development of self-efficacy in children. Self-efficacy means personal judgement about one's capability to organize his behavior in a specific situation. Perceived efficacy can have diverse effects on behavior, thought patterns and affective arousal. People acquire their efficacy information from their performance accomplishments, vicarious experiences, verbal persuasion and their physiological states. In this paper, I argue that two factors, psychological and environmental factor, contribute to the development of children's self-efficacy. Specifically reward, attributional feedback, social comparision and goal setting are classified to psychological factor and home environment, school environment and social environment belong to environmental factor. Since not many studies have been done in this area, in this paper I also suggest some directions for future research.

• International Journal of Automotive Technology
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• v.5 no.2
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• pp.95-108
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• 2004

Lanekeeping assistance has the potential to save thousands of lives every year by preventing accidental road departure. This paper presents experimental validation of a potential field lanekeeping assistance system with quantitative performance guarantees. The lanekeeping system is implemented on a 1997 Corvette modified for steer-by-wire capability. With no mechanical connection between the hand wheel and road wheels the lanekeeping system can add steering inputs independently from the driver. Implementation of the lanekeeping system uses a novel combination of a multi-antenna Global Positioning System (GPS) and precision road maps. Preliminary experimental data shows that this control scheme performs extremely well for driver assistance and closely matches simulation results, verifying previous theoretical guarantees for safety. These results also motivate future work which will focus on interaction with the driver.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.2
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• pp.245-249
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• 2014

Wireless power transfer (WPT) system is very attractive because it removes power cables from home appliances, office equipments and battery chargers for electric vehicles. In this paper, non-radiative WPT systems studied recently are claimed to be technologically or theoretically identical in operation irrespective of the number of coils. Especially, 2-coil and 3-coil systems are compared in detail. It is also shown that multiplicity of coils does not increase power transfer capability.

• Membrane and Water Treatment
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• v.7 no.5
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• pp.433-449
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• 2016

The successful application of cleaning protocols is vital for optimized filtration processes. A series of experiments with an ultrafiltration ceramic tubular membrane were carried out for the foulants dextran and carboxymethyl cellulose. Firstly, the impact on fouling of concentration changes was investigated with the increase in resistance being used as the key parameter. In the second phase, removal of reversible fouling was also investigated by employing intermittent rinsing consisting of a cold water rinse followed by a hot one. A comparative analysis for both foulants is reported. Across a range of concentrations and for both foulants, the reduction in resistance due to rinsing was found to depend upon concentration (C); it changed as $C^n$ where n was found to be 0.3. A plausible semi-theoretical explanation is given. Thirdly, for both foulants, the application of a combination of strong alkaline solutions with oxidizing agent (mainly sodium hypochlorite) followed by acid was found to be appropriate for cleaning of the ceramic membrane. The effect of increased temperature for cleaning agents followed by a warm water rinse contributed positively to the cleaning capability.

• Journal of Technology Innovation
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• v.25 no.4
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• pp.47-77
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• 2017

This paper critically examines research trends on the relationship between technological innovation and economic growth in Korea. There are different views on the role of innovation in economic growth including Exogenous and Endogenous Growth, National Innovation System, Technological Capabilities, Economic Catch-up discourses and so on. According to these theoretical discourses, existing studies about Korea are reviewed in a critical way and then future research work is proposed through such a critical review and reflection.

• Journal of Korean Academy of Nursing Administration
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• v.23 no.2
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• pp.181-190
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• 2017

Purpose: This study was done to clarify the concept analysis of positive psychological capital. Methods: Walker and Avant's concept analysis process was used in this study. CINAHL, ProQuest, Web of science, NDSL, RISS databases from 2004 to 2016 were searched using the keywords 'Positive psychological capital' and 'PsyCap'. Sixty-one relevant articles and three book were finally selected. Results: Analysis of identified literature indicated that positive psychological capital attributes were developable potential, positive cognition, expression of emotion, multiple psychological capability, and resources with positive effect. The antecedents were goal achievement, training, leader's motivation, and supportive organizational environment. The consequences were overall wellbeing which is composed of individual's physical, psychological and social wellbeing and enhancement of work outcome. Conclusion: The findings in this study provide a definition of the concept of positive psychological capital and theoretical evidence for the future research for nurses including program development.

• Journal of the Korean Electrochemical Society
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• v.9 no.1
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• pp.10-18
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• 2006

This article is concerned with the overview of the activated carbon fibers. Firstly, this review provides a comprehensive survey of the overall processes for the synthesis of the activated carbon fibers from the carbonaceous materials. Subsequently, the physicochemical properties such as pore structures and surface oxygen functional groups of the activated carbon fibers were discussed in detail. Finally, as electrochemical applications of the activated carbon fibers to electrode materials for electric double-layer capacitor (EDLC), the electrochemical characteristics of the activated carbon fiber electrodes and the various methods to improve the capacitance and rate capability were introduced. In particular, the effect of pore length distribution (PLD) on kinetics of double-layer charging/discharging was discussed based upon the experimental and theoretical results in our work. And then we discussed in detail the applications of the activated carbon fibers to adsorbent materials for purification of liquid and gas.