• International Journal of Contents
• /
• 제10권3호
• /
• pp.55-63
• /
• 2014

Existing science education that excludes narrative thinking impedes the understanding of the context of workbook content. The object of this research is to develop a storytelling-learning program based on narrative thinking to elevate learners' interest in science and expand their inventive problem-solving abilities. Following an analysis of the current Korean curriculum, eight types of storytelling materials that utilize local content were developed for grades 7-9. The learning program used quest storytelling and was designed such that learning activities such as investigation, discussion, and experimentation were included in the process of solving each quest. Learners experienced an interest in storytelling learning resulting from participation in this storytelling-learning program. Moreover, learners demonstrated inventive problem-solving abilities in the process of completing the stories. During the process of assembling the storytelling materials, the students interacted with enthusiasm and generated ideas. The teachers indicated a positive feedback to the storytelling program as a new attempt to stimulate learners' interests. In the future, with continuous development and application, storytelling-science-learning programs that base science learning on narrative thinking are expected to be successful.

• International Journal of Contents
• /
• 제12권1호
• /
• pp.54-59
• /
• 2016

The purpose of this paper is to discover how the use of digital applications can affect students' attitudes toward positive classroom participation and performance in learning a foreign language. Participants of this study were 128 students who took a foreign language class at a high school in central Korea. To find out students' perceptions and attitudes toward the effect of using a digital application for their foreign language study, online questionnaire and focus-group interview were conducted. Our research findings revealed that these students could engage in active language learning and experience learning improvement while studying a foreign language with digital applications. The improvement was possible by creating more interactive activities and quizzes. In addition, the digital application provided students immediate feedback. It gave students and teachers various motivations beyond the traditional 'chalk and talk' format of text-only-classes. This study provides an overview of the usefulness of digital application. In addition, it provides understanding for students' perceptions and involvement using digital application in a foreign language classroom.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1988년도 추계학술대회 논문집 학회본부
• /
• pp.414-417
• /
• 1988

This paper presents a study on the operation of a digitally controlled DC servo motor drive at low speed region. Two schemes aiming to improve the transient behavior of the speed control system are considered. The first scheme is the current positive feedback scheme to reduce the sensitivity of the system with respect to the load torque variations. The second one is the speed observer based on a motor model. Finally, the two schemes are studied by simulation and then verified experimetally using a prototype DC motor drive.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2005년도 심포지엄 논문집 정보 및 제어부문
• /
• pp.66-68
• /
• 2005

DC motor is easy to control and can make torque easily. DC motor uses wide range. But DCmotor have limited by using a brush and structural complexity. But, BLDC doesn't have brush so that is more simple than DC motor, and the rotor of BLDC motor is made by permanent magnet that dose not need to make a fixed flux speed for flux current. BLDC motor is very efficiency, controllable, and reliable. This paper presents an error detection with a BLDC motor current. Generally, BLDC motor current is used to current feedback, so that can make a critical fault in the system. this paper suggests to detect error by inspection of threshold current value both positive and negative.

• 수산해양교육연구
• /
• 제23권2호
• /
• pp.234-243
• /
• 2011

Mindmap is effective method to analyze informations. And, through mindmap, students can be able to grow their ability of logical reconstruction. In Modern society, people have been developing IT technology and variety of portable devices. So, Educational environments have been being changed accordingly, too. In this study, we have implemented mindmap application that based on android to share the group member's thinking. To effective sharing, we have used mindmap technique and photo attachment feature. In this study, expert evaluation has been carried out by elementary current teachers. In result of this expert evaluation, we have obtained positive feedback at sharing function, input technique and information display. Also, teachers have gave feedbacks that they are willing to use this application in class, if classroom environment is possible.

• ETRI Journal
• /
• 제29권6호
• /
• pp.785-793
• /
• 2007

In this paper, we present an integrated rail-to-rail fully differential operational transconductance amplifier (OTA) working at low-supply voltages (1.5 V) with reduced power consumption and showing high DC gain. An embedded adaptive biasing circuit makes it possible to obtain low stand-by power dissipation (lower than 0.17 mW in the rail-to-rail version), while the high DC gain (over 78 dB) is ensured by positive feedback. The circuit, fabricated in a standard CMOS integrated technology (AMS 0.35 ${\mu}m$), presents a 37 V/${\mu}s$ slew-rate for a capacitive load of 15 pF. Experimental results and high values of two quality factors, or figures of merit, show the validity of the proposed OTA, when compared with other OTA configurations.

• Transactions on Control, Automation and Systems Engineering
• /
• 제1권2호
• /
• pp.106-112
• /
• 1999

This paper presents an H$\infty$ controller design method for linear systems with time-varying delayed states, inputs, and measurement outputs. Using a Lyapounov unctional , the stability for delay systems is discussed independently of time delays . And a sufficient condition for the existence of H$\infty$ controllers of n-th order is given in terms of three matrix inequalities. Based on the positive-definite solutions of their matrix inequalities, we briefly explain how to construct H$\infty$ construct H$\infty$ controller, which stabilizes time-delay systems independently of delays and guarantees an H$\infty$ norm bound.

• 한국정보디스플레이학회:학술대회논문집
• /
• 한국정보디스플레이학회 2003년도 International Meeting on Information Display
• /
• pp.130-133
• /
• 2003

Vertical Colour Selection (VCS) is an option for slim CRTs with increased sharpness and brightness. The direction of self-convergence of the DY is changed to vertical in order to obtain better spot uniformity, but the line scan direction remains horizontal. Hence, no video conversion is needed, contrary to transposed scan. In this paper we address two issues: First, there is a high risk of moire, since the scan lines and the phosphor stripes are parallel. We propose a feedback mechanism guiding the electron beams towards the middle of the mask slots. As positive side effects, the brightness is improved and the shadow mask can be made of a cheap type of steel. Secondly, VCS deflection coils have to satisfy different requirements than coils in ordinary CRTs. We discuss the design rules for self-convergent VCS coils and present simulation results.

• Journal of Information Technology Applications and Management
• /
• 제9권3호
• /
• pp.97-111
• /
• 2002

This paper attempts to provide an overview of relationship between the characteristics of the network and competitive strategies. We review the theoretical background of the efficiency of network, which Is very important for the network-based industries. Network externality, positive feedback effects, bandwagon effects, economies of scale, economies of scope in network-base businesses are reviewed. Various network situations, including interconnection, and strategies are also discussed. In this purpose, simple but meaningful examples and cases are used to show the economic goals and means of network competition strategies. We try to link network strategies to the generic strategies and coopetition suggested by Porter and by Brandenburger and Nalebuff respectively. Since this study is an exploratory research, further studies on more complex network situation in the real work can be executed with taking advantage of this effort.

• Transactions on Control, Automation and Systems Engineering
• /
• 제1권1호
• /
• pp.44-49
• /
• 1999

This paper presents a new T-S(Tae-Sugeno) fuzzy controller design method satisfying the output energy bound. Maximum output energy via a quadratic Lyapunov function to obtain the bound on output energy is derived. LMI(Linear Matrix Inequality) problems which satisfy an output energy bound for both of the continuous-time and discrete-time T-S fuzzy control system are also derived. Solving these LMIs simultaneously, we find a common symmetric positive definite matrix P which guarantees the global asymptotic stability of the system and stable feedback gains K's satisfying the output energy bound. A simple example demonstrates validity of the proposed design method.