• 대한수학회보
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• 제31권1호
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• pp.1-14
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• 1994

In the recent several years the theory of impulsive differential equations has made a rapid progress (see [1] and [2] and the references there). The questions of stability and periodicity of the solutions of these equations have been elaborated in sufficient details while their asymptotic behaviour has been little studied. In the present paper the asymptotic behaviour of the solutions of linear impulsive differential equations is investigated, generalizing the results of J. W. Macki and J.S. Muldowney, 1970 [3], related to ordinary differential equations without impulses.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2002년도 ICCAS
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• pp.84.2-84
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• 2002

$\textbullet$ The dynamic model of a floating human body is derived $\textbullet$ Introduction to impact model for human body $\textbullet$ Analysis of external impulse on the sole $\textbullet$ Analysis of internal impulse at the joints $\textbullet$ It is shown through simulation that the internal impulses for two different configurations

• Journal of the Korean Society for Industrial and Applied Mathematics
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• 제16권2호
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• pp.93-105
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• 2012

In this paper, we consider the controllability of a certain class of impulsive neutral evolution differential equations in Banach spaces. Sufficient conditions for controllability are obtained by using the Hausdorff measure of noncompactness and Monch fixed point theorem under the assumption of noncompactness of the evolution system.

• 대한수학회지
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• 제56권1호
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• pp.127-147
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• 2019

In this paper we establish some new explicit solutions for impulsive linear fractional differential equations with impulses at fixed times, which provides a handy tool in deriving singular integral-sum inequalities and an impulsive fractional comparison principle. Thus we study the Mittag-Leffler stability of impulsive differential equations with the Caputo fractional derivative by using the impulsive fractional comparison principle and piecewise continuous functions of Lyapunov's method. Also, we give some examples to illustrate our results.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• 제21권2호
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• pp.127-133
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• 2018

Purpose: For 3 consecutive years from 2012-2014, we analyzed the causative factors for why the Jeju Island had the highest obesity prevalences of school children among the 15 provinces in Korea. Methods: From our analysis of 28,026 elementary school children with obesity or normal weight in the 15 provinces, we analyzed 12 factors related to eating habits, exercise habits, lifestyle, and mental health. The differences between the obese and normal weight children were researched. Finally, Jeju was compared with Seoul, which has the lowest obesity prevalence in school age children. Statistical analysis was performed using the chi square test of PASW Statistics ver. 18.0. Results: Compared to the normal weight group, the obese group had significantly higher rates of consuming soft drinks (p<0.001), fast food intake (p=0.019), skipping breakfast (p<0.001), insufficient sleep (p<0.001), bullying experiences (p=0.001) and runaway impulses (p=0.012). Compared to Seoul, Jeju Island had significantly higher rates of Ramen intake (3.4% vs. 5.4%, p=0.021) and meat intake (46.0% vs. 52.9%, p=0.003). On the other hand, Jeju Island was significantly lower than was Seoul in their fruit intake (83.4% vs. 67.1%, p<0.001), vegetable intake (71.4% vs. 64.2%, p=0.001), and intense physical activity (63.4% vs. 47.7%, p<0.001). Meanwhile, insufficient sleep (15.4% vs. 9.6%, p<0.001) and runaway impulses (5.6% vs. 3.3%, p=0.027) in children were significantly lower in Jeju Island than in Seoul. Conclusion: The results of the obesity factor analysis of elementary school students in Jeju Island can be used as useful educational material for lowering the obesity prevalence in Jeju community.

• The Korean Journal of Physiology
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• 제5권2호
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• pp.71-78
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• 1971

Anesthetized dogs were tilted from horizontal to the upright and head down position. Tilting to the upright position was followed by an increase in heart rate. In the head down position a decreased heart rate was obtained. The arterial blood pressure was decreased in the upright position and was decreased markedly in the head down position. The central venous pressure was decreased in the upright position and was markedly decreased down to the negative pressure in the head down position. The respiratory rate was slightly increased in the upright position comparing to that in the horizontal position. No remarkable changes were noted in the head down position. From the above results the following factors were discussed The decreased arterial blood pressure during the upright position was supposed to be the secondary effect from the diminished venous return that was suggested by the decreased central venous pressure. The decreased arterial blood pressure in the head down position was also supposed as the above reason as the diminished central venous pressure during the tilt. In addition the cardioinhibitory effects originated from the baroreceptors might have been operated during head down tilting. In the heart rate there was slight tachycardia in the upright position this was assumed as the abolished cardioinhibitory impulses from the baroreceptor in the upright position. On the contrary, despite of the decrease of arterial blood pressure in the head down position as well as in the upright, the bradycardia have been appeared. This was suggestive of cardioinhibitory impulses from the baroreceptors which was stretched during head down tilting. From the above findings there is a possibility of continous cardioinhibitory responses during head down tilting for this kind of the short period of 10 minutes which was chosed in this study.

• 제어로봇시스템학회논문지
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• 제11권6호
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• pp.543-549
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• 2005

This paper deals with modeling and analysis fer the landing motion of a human-body model. First, the dynamic model of a floating human body is derived. The external impulse exerted on the ground as well as the internal impulse experienced at the joints of the human body model is analyzed. Second, a motion planning algorithm exploiting the kinematic redundancy is suggested to ensure stability in terms of ZMP stability condition during a series of landing phases. Four phases of landing motion are investigated. In simulation, the external and internal impulses experienced at the human joints and the ZMP history resulting from the motion planning are analyzed for two different configurations. h desired landing posture is suggested by comparison of the simulation results.

• 대한치과의사협회지
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• 제56권1호
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• pp.49-57
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• 2018

The most widely used method of pain control in dental practice is to block the pathway of painful impulses by local anesthesia. For a maximum effect of pain control at outpatient minor operation, regional anesthesia including nerve block must be performed. This issue includes various dental local anesthetic techniques on mandible, maxilla and considerations for selection of dental local anesthetics according to patient's age, duration of operation. Additionally, current conscious sedation technique combined with local anesthesia will be introduced for control of patient's anxiousness. Based on patient's general condition, severity of operation, local anesthesia sometimes must be changed into general anesthesia to avoid failure of dental practice. The exact choice of anesthetic techniques for minor operations at dental outpatient clinic must not be underestimated for complete success of pain control.

• 대한기계학회논문집B
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• 제28권10호
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• pp.1264-1270
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• 2004

In this paper research on micro solid propellant thruster is reported. Micro solid propellant thruster has four basic components; micro combustion chamber, micro nozzle, solid propellant and micro igniter. In this research igniter, solid propellant and combustion chamber are focused. Micro igniter was fabricated through typical micromachining and the effect of geometry was evaluated. The characteristic of solid propellant was investigated to observe burning characteristic and to obtain burning velocity. Change of thrust force and the amount of energy loss following scale down at micro combustion chamber were estimated by numerical simulation based on empirical data and through the calculation normalized specific impulses were compared to figure out the efficiency of combustion chamber.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 학술대회 논문집 정보 및 제어부문
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• pp.450-452
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• 2004

Every movement, perception and thought we perform is associated with distinct neural activation patterns. Neurons in the brain communicate with each other by sending electrical impulses that produce currents. These currents give rise to electrical fields that can be measured outside the head. It shows some variation on the electroencephalographic signals. In recent devices, the EEG signals measured from head surface are a sum of all the momentary brain activation. With these EEG signals, it is difficult to distinguish the patterns correlated with a certain event from the signals. However, the system must discriminate some patterns with some events especially for any kind of device as a brain control interface system. In this experiment, the sensory-motor cortex of humans has been extensively studied. Activation related to several movements on both sides of the sensory-motor cortices in imaginary. The activation patterns during imagination of several movements resemble the activation patterns during preparation of movements. The result represents the system based on the optimal filters discriminated at least 60% of mental imageries.