• 제어로봇시스템학회논문지
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• 제12권4호
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• pp.405-410
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• 2006

This paper presents the design of a USB home controller and a home control system that specially is focused on controlling home appliances as a part of home network systems, the implementation of the USB device access class in an OSGi service platform and a home security system as an application. Designed USB home controllers are able to control various home appliances. They can be used not only to control big home appliances like a boiler but also to control small home appliances like a toaster because they are low-cost solutions. The USB home controller supports real time control using the interrupt transfer of the USB specification. And It is easy to use by homemakers who have no technical knowledge of the system because they just plug and unplug it in a home server then it automatically joins and leaves a home control system. This technique is based on hot-plug and the USB Device Access class in an OSGi Service Platform. The USB Device Access class supports the coordination of automatic detection and attachment of the USB home controller on an OSGi Service Platform, and it downloads and installs device drivers on demand. For an application, we implemented and tested a home security system using two USB home controllers and a CDMA module.

• 한국산업융합학회 논문집
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• 제20권5호
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• pp.425-430
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• 2017

This study propose CAE analysis of fire damper and design of the damper control system. Through the design of the damper system for ANSYS-CFX heat transfer. As a result of the analysis, continuance equation of the damper control. Climate system. Finaily, We have obtained a fire damper solution by using orthogonal array. The fire damper of the set of fixture and alveolus are made by using a CAE software. Also, the optimum design offshore structures. The new H-120 class fire damper was designed. In the near future, fire resistance test was carried out to obtain class H-120 thermal insulation of fire dampers according to a hydrocarbon fire conditions. The test results showed that the insulation of the damper blade was an important factor in the fireproof performance of fire dampers concerning the coaming length minimum 500mm on the unexposed side as specified test standard.

• 대한지구과학교육학회지
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• 제4권2호
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• pp.186-193
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• 2011

The aim of this study is to find out the effect of reading aloud science books on change of attitude toward the science, interest of instruction. Participants included 52 elementary school students. For this study, two classes were divided into experimental class and control class. The control class takes a regular instructions and the experimental class takes a reading aloud instructions. Two chapter were selected, 'Volcano and Rocks' and 'Family of the Sun', for this study. Students were treated for 12 hours. All the results were analyzed quantitatively and following conclusions were made. The students' scientific attitude in the experimental class were higher than those of students in the control class. However, according to statistical analysis, this result is meaningless. In the sub-parts, critical ability, cooperation and creativity were improved meaningfully. Instruction with reading aloud science books didn't show a meaningful difference in interest of instruction. However, in the sub-part, they showed meaningful improvement in attention and relevance.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 하계종합학술대회 논문집(5)
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• pp.13-16
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• 2000

This paper presents a simple class-D stereo amplifier using 3-phase full bridge circuit configurations which is controlled by a new current control switching method. Although this class-D amplifier has an only one current control loop with the proposed switching method, a good performance can be obtained. In this paper, a strategy for driving stereo signal amplifier with 3-phase full bridge is discussed. With the experimental results, usefulness of the proposed amplifier is confirmed.

• 대한지구과학교육학회지
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• 제5권1호
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• pp.95-104
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• 2012

The purpose of this study is to examine what effects the experiment class to stress discussion of small groups in scientific experiment class of the elementary school has on scientific achievement and attitude on the science of the students comparing to the usual scientific experiment class. For that purpose, this study has divided 49 students at the 6th grade of the M elementary school in P City into test groups of 24 students and control groups of 25 students. Classes have been progressed by giving sufficient time to the test groups for discussion by each small groups after experiment while by allowing the control groups to finish the experiment with arrangement of the experiment results. Conclusions of this study include: First, the more familiar the experiment materials are and the easier the experiment procedures are to be operated by the students, the more actively the small group discussion activities have been deployed. It shows that the students need a certain level of background knowledge before experiment for vital discussing activities. Second, it is appeared that the test groups given the scientific experiment class stressing small group discussing activity have significantly high scores comparing to the control groups given the existing scientific experiment class. It shows that the small group discussing activities have effects on promoting understanding of the students on the scientific achievement for the scientific experiment class. Third, it is appeared that the test groups given the scientific experiment class stressing small group discussing activity significantly high scores on attitude about the science comparing to the control groups given the existing scientific experiment class. It is considered that the students could have opportunities to compare their own thoughts with others and to have reflective thought to change their thoughts through the small group discussing activity. As shown above, it shows that the experiment class to stress discussing activities is more effective to increase scientific achievement and attitude about the science than the scientific experiment class to get and arrange the experiment results from the existing experiment classes.

• 수산해양교육연구
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• 제25권6호
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• pp.1324-1335
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• 2013

The purpose of this study was to examine the effects of PCK designed instruction on academic achievement and self-efficacy for underachievers in science of elementary school. The hypotheses were as follows: First, PCK designed science instruction would improve academic achievement of the children. Second, PCK designed science instruction would improve academic self- efficacy of the children. The subject was 14 students of forth graders of elementary school who are underachievers in science class. For group composition, self efficacy test and science achievement test were conducted and they were divided into experimental group and control group. Each group has 7 participants. A total of 16 sessions were conducted for 8 weeks, twice per week, with experimental group were taught PCK designed classes while control group were taught teacher-led explanation type class. The result of statistical analyses were as follows: First, the experimental group in PCK designed class showed more improvement on academic achievement than the control group in the teacher-led explanation type class. Second, the experimental group in PCK designed class showed more improvement on self efficacy than the control group in the teacher-led explanation type class.

• 전자공학회논문지SC
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• 제40권2호
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• pp.19-25
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• 2003

본 논문에서는 주어진 작업을 반복적으로 수행하는 다입력 다출력 비선형시스템에 대하여 시스템의 (벡터)상대차수 개념을 이용한 확장된 형태의 직접학습제어를 제안한다. 기존의 직접학습제어가 적용될 수 있는 시스템은 상대차수가 제한적인 시스템임을 보이고 고차의 상대차수를 갖는 시스템에 적용 가능한 제어 법칙을 제시한다. 이 제어법칙을 이용하여 다른 형태의 출력 궤적들에 대한 학습을 통하여 얻어진 제어입력들로부터 새로 주어진 원하는 출력 궤적에 대응하는 제어입력을 직접적으로 생성한다. 제안된 직접학습제어의 타당성 및 성능을 보이기 위하여 2축 스카라 로봇에 대한 궤적추종제어의 시뮬레이션 결과를 제시한다

• International Journal of Control, Automation, and Systems
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• 제5권5호
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• pp.547-558
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• 2007

This paper proposes a simpler solution to the stabilization problem of a special class of nonlinear underactuated mechanical systems which includes widely studied benchmark systems like Inertia Wheel Pendulum, TORA and Acrobot. Complex internal dynamics and lack of exact feedback linearizibility of these systems makes design of control law a challenging task. Stabilization of these systems has been achieved using Energy Shaping and damping injection and Backstepping technique. Former results in hybrid or switching architectures that make stability analysis complicated whereas use of backstepping some times requires closed form explicit solutions of highly nonlinear equations resulting from partial feedback linearization. It also exhibits the phenomenon of explosions of terms resulting in a highly complicated control law. Exploiting recently introduced Dynamic Surface Control technique and using control Lyapunov function method, a novel nonlinear controller design is presented as a solution to these problems. The stability of the closed loop system is analyzed by exploiting its two-time scale nature and applying concepts from Singular Perturbation Theory. The design procedure is shown to be simpler and more intuitive than existing designs. Design has been applied to important benchmark systems belonging to the class demonstrating controller design simplicity. Advantages over conventional Energy Shaping and Backstepping controllers are analyzed theoretically and performance is verified using numerical simulations.

• Journal of Community Nutrition
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• 제5권3호
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• pp.151-159
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• 2003

The purpose of this study was to investigate the difference in dietary attitudes, dietary behaviors and health-related lifestyles among Korean college students (392 males, 808 females) participating in a web class of nutrition education. This cross-sectional survey was conducted by a self-administered questionnaire and data was analyzed by SPSS program. Most female subjects with weight-control attempt had eating habit problems such as overeating and food jags. The female subjects with weight-control attempt showed significantly higher rate of skipping dinner compared to those without weight-control attempt. As for frequency of exercise, the subjects with weight-control attempt exercised more frequently compared to those without weight-control attempt. In subjects, weight-control attempt was significantly associated with exercise. Nutrient adequacy ratio and mean adequacy ratio of the subjects with weight-control attempt were significantly lower compared to those without weight-control attempt. These results suggest that skipping dinner or exercise might be used as weight-control methods in Korean college female students participating in a nutrition education class via the internet.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1995년도 Proceedings of the Korea Automation Control Conference, 10th (KACC); Seoul, Korea; 23-25 Oct. 1995
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• pp.416-419
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• 1995

A finite-dimensional approximation technique is developed for a class of spectral systems with input and output operators which are unbounded. A corresponding bounding technique on the frequency-response error is also established for control system design. Our goal is to construct an uncertainty model including a nominal plant and its error bounds so that the results from robust linear control theory can be applied to guarantee a closed loop control performance. We demonstrate by numerical example that these techniques are applicable, with a modest computational burden, to a wide class of distributed parameter system plants.