• Journal of Institute of Control, Robotics and Systems
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• v.17 no.10
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• pp.1006-1013
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• 2011

In this paper, we propose an optimal posture control law for an unmanned bicycle by deriving linear bicycle model from fully nonlinear differential equations. We calculate each equilibrium point of a bicycle under any given turning radius and angular speed of rear wheel. There is only one equilibrium point when a bicycle goes straight, while there are a lot of equilibrium points in case of turning. We present an optimal equilibrium point which makes the leaning input minimum when a bicycle is turning. As human riders give rolling torque by moving center of gravity of a body, many previous studies use a movable mass to move center of gravity like humans do. Instead we propose a propeller as a new leaning input which generates rolling torque. The propeller thrust input makes bicycle model simpler and removes input magnitude constraint unlike a movable mass. The proposed controller can hold optimal equilibrium points using both steering input and leaning input. The simulation results on linear control for circular motion are demonstrated to show the validity of the proposed approach.

• Wind and Structures
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• v.1 no.1
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• pp.1-23
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• 1998

This paper describes wind investigations for the Leaning Tower of Pisa which were conducted as part of an overall evaluation of its behaviour. Normally a short, stiff and heavy building would not be a candidate for detailed wind analyses. However, because of extremely high soil pressures developed from its inclination, there has been increasing concern that environmental loading such as wind actions could combine with existing conditions to cause the collapse of the tower. The studies involved wind assessment at the site as a function of wind direction, analysis of historical wind data to determine extreme wind probabilities of occurrence, estimation of structural properties, analytical and boundary layer wind tunnel investigations of wind loads and evaluation of the response with special concern for loads in the direction of inclination of the tower and significant wake effects from the neighboring cathedral for critical wind directions. The conclusions discuss the role of wind on structural safety, the precision of results attained and possible future studies involving field measurements aimed at validating or improving the analytical and boundary layer wind tunnel based assessments.

• Journal of the Korea Convergence Society
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• v.11 no.5
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• pp.43-49
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• 2020

The purpose of this study was to determine whether PNF respiratory exercise increases the vital capacity and maximal voluntary volume of 20s normal adults by 45° leaning sitting position. Twenty normal adults in their 20s were randomly assigned to an experimental group and control group. Over the course of four weeks, the experimental group participated in PNF respiration exercises by 45° leaning position for 30 minutes three per week. And the control group participated in diaphragm respiration exercises by 45° leaning position for 30 minutes three times per week. Subjects were assessed post-test by measurement of vital capacity, maximal voluntary volume. Our findings show that the experimental group had significant improvements in vital capacity, maximal voluntary volume(p<.05). In this study, the experimental group showed more improvement in pulmonary function, which indicates that the PNF respiratory exercise by 45° leaning sitting position is effective at increasing the pulmonary function of normal adults.

• Journal of the Korean Professional Engineers Association
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• v.38 no.5
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• pp.23-26
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• 2005

• Journal of Ecology and Environment
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• v.31 no.2
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• pp.147-151
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• 2008

Feeding methods of five species of herons and egrets were studied in an agricultural landscape in Asan city, Chungcheongnam-do, Korea in 2006. Grey herons primarily hunted while standing, whereas great egrets fed while walking slowly. Two smaller species, little and cattle egrets, were active foragers, feeding both while walking quickly and walking slowly. Little egrets were the only species using the foot stirring method. The medium-sized heron, intermediate egrets, foraged mainly while walking slowly or leaning. For grey herons, great egrets and little egrets, the frequency of use of different feeding methods was different between habitats: these species used the leaning method more frequently in rice fields than in reservoirs and ditches. Also, most herons (all species other than great egrets) showed seasonal changes in their feeding methods that are related to changes in habitat condition.

• International Journal of Knowledge Content Development & Technology
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• v.5 no.2
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• pp.103-122
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• 2015

This study examined student satisfaction with e-learning experiences in order to determine which factors had the greatest impact on reports of satisfaction among students at Konkuk University. We surveyed 4,889 students enrolled in e-learning courses and analyzed 830 completed questionnaires to identify factors that influence student satisfaction with e-learning. Results showed significant correlations between system factors and satisfaction ($R^2=0.577$; p = 0.000). The system factor with the greatest impact on satisfaction was course attendance rate (0.224; p = 0.000).

• Journal of Korean Elementary Science Education
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• v.30 no.4
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• pp.615-623
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• 2011

The purpose of this study was to analyse of the effects on students' leaning types through the Creative Problem Solving Teaching Model in elementary science class. The results of this study were as follows; 1. experimental group in creative problem solving, scientific inquiry skills and academic achievement was higher than control group which was statistically significant (p<.05). 2. for the students' learning type the experimental group was distributed to accommodators (35.7%), divergers (25.0%), convergers (25.0%) and assimilators (14.3%). 3. after the program treatment, assimilator type group students in creative problem solving were higher than other type group students. 4. diverger and assimilator group students in academic achievement, diverger group students in scientific inquiry skills, and accommodator group students in scientific attitude were higher than other groups.

• Communications of Mathematical Education
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• v.24 no.3
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• pp.777-792
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• 2010

It is to design diverse teaching methods to construct competitive knowledge-based society and to design teaching methods suitable to Korean conditions. The study reviewed Ausubel's meaningful learning especially subsumption theory as a plan to make students understand math and receive it meaningfully through explanatory class. Analyzing meaning and conditions of Ausubel's meaningful learning can make utility of significant explanatory learning in education of mathematics easier.

• Proceedings of the Korea Contents Association Conference
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• 2008.05a
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• pp.394-397
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• 2008

It is easy that students give up his study in e-learning environments. So it is critical for success of e-learning school to encourage students' aspiration to graduate study. This study examines the effect of sense of community to aspiration to graduate study and school loyalty in e-leaning school. I found that sense of community effect to school identification and that school identification effect to aspiration to graduate study and school loyalty.

• Korean Journal of Veterinary Research
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• v.61 no.4
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• pp.35.1-35.4
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• 2021

Following intravenous (IV) administration of diazepam as a preanesthetic agent, sudden balance impairment, such as falling, leaning, and rolling, was identified in 2 canine cases. The 2 dogs were anesthetized for brain magnetic resonance scan to diagnose about a history of head tilt. After end of the diagnostic procedures, during the anesthetic recovery period, balance impairment was also observed. However, the symptoms gradually ceased by IV administration of flumazenil. These 2 canine cases indicated that diazepam premedication was responsible for the acute balance impairment.