• Journal of Broadcast Engineering
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• v.21 no.2
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• pp.268-271
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• 2016

In video sequences, foreground object detection being composed of a background model and a background subtraction is an important part of diverse computer vision applications. However, object detection might fail in sudden illumination changes. In this letter, an illumination-robust background detection is proposed to address this problem. The method can provide quick adaption to current illumination condition using two background models with different adaption rates. Since the proposed method is a non-parametric approach, experimental results show that the proposed algorithm outperforms several state-of-art non-parametric approaches and provides low computational cost.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.43 no.8
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• pp.684-691
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• 2015

A sudden increase in combustion pressure is observed in the ducted rocket combustion test equipped with pipe shaped and converging nozzle exhaust tubes. This study aims to understand the physical mechanism of abrupt change in combustion pressure using thermal choking in the exhaust tube. Results confirmed that the thermal choking of the flow inside the exhaust tube was responsible for the sudden increase in combustion pressure. Also, high pressure exponent of solid propellants is critical sensitive to the occurrence of thermal choking exhaust pipe. Additionally, numerical simulation showed that the sudden increase in combustion pressure was less possible in diverging pipe because thermal choking is more reluctant to occur.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.24 no.65
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• pp.51-63
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• 2001

The present experiment investigated the possibility of evaluating of the human sensibility contingent on the speed and modes of driving using the responses from the autonomic nervous system, subjective assessments, Simulator Sickness (55) in dynamic simulator. The three conditions of the speed of driving were 40 $\pm$ 10 km/h, 100$\pm$10 km/h, 160 $\pm$ 10 km/h, and the participant was instructed to drive the car for three minutes on the elliptical track. It is programed in such a way that the modes of driving can be changed smoothly using road DB in Dynamic Simulator, and for signifying the change of the condition the road signs were used. The instruction was given to the participant to drive the car on the fixed speed of 20 km/h for 30 seconds, then to drive the car on sudden-start mode of driving from the 20 km/h to 160 km/h within 10 seconds. For the sudden-stop mode of driving, it was instructed that stop the car from the speed of 160km/h to 20km/h within 10 seconds when the subject see the road sign, then drive the car at the fixed speed of 20 km/h for 30 seconds. The results of the subjcetive assessment showed that the level of pleasantness and the tension was increased, and physiological response showed that the level of activity of the autonomic responses were also increased as the speed of the car increased. Also, for results on the driving modes showed that the level of pleasantness was highest for the sudden-stop, next highest was sudden-start, and the lowest was 20 km/h fixed speed condition for the subjective assessment, and tile order of the level of activation of the autonomic nervous system showed the same results as above. From the results of the present study it was concluded that the presentation and evaluation of the stimulus for the human sensitivity is possible in dynamic simulator.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.10a
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• pp.221-223
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• 2016

Currently in the automobile market, models with many convenient functions combined with IT have been released. This change has a strength that there could be many convenient and useful functions related to driving while flaws of vehicles caused by malfunctions of these electronic equipments could trigger serious incidents. Among them, the sudden unintended acceleration considered as the most serious is a serious flaw that could threaten driver's life. However, the causes for sudden acceleration incidents have not been clearly investigated with no coping measures. As manufacturers shift the responsibility to drivers' carelessness, drivers' burden is continuously increasing. Thus, this paper designed the system to cope with sudden acceleration incidents by changing conditions of controlling parts like accelerator and brake, and internal image of the driver's seat into data through the integrated module.

• Hwankyungkyoyuk
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• v.22 no.1
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• pp.68-82
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• 2009

Global climate change is associated with all of the human activity, and its sudden change can be taken an issue of the serious environmental problem in our human society. The purpose of this study is to develope the goal and the content system for the climate change education. As a result, first, according to the questionnaires on climate change, students from Grade 3 to Grade 10 seem to interpret it as fragmentary perspectives. In addition, in terms of students' own actions as the corresponding strategy to climate change, the higher their grades were, the lower their actions were. Second, the development goal on climate change and its educational directions were set by reflecting students' perception. The education goal on climate change is to perceive the changing environment by understanding phenomena of climate change, to propose plans that can mitigate and adjust climate change through a variety of research, and to keep practicing the proposed plans as a member of a community for the global environment. Third, fields and items of educational contents to climate change were created and drawn out. The content system is composed of 'basic science of climate change', 'relationship with climate change', and 'coping with climate change'. Furthermore, concrete contents for the climate change education in elementary school were suggested so that its goal and content system can be used in the existing curriculum.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.1045_1046
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• 2009

This paper presents an active and reactive power compensator for the wind power system with squirrel-cage induction generator. The developed system is able to continuously compensate the active and reactive power. The 3-phase inverter operates for the compensation of reactive power, while the DC/DC converter with super-capacitors operates for the compensation of active power. The proposed compensator can be expected that developed system may be used to compensated the abrupt power variation due to sudden change of wind speed or sudden power-drop by tower effect. It can be also applied for the distributed generation and the Micro-Grid.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2012.05a
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• pp.239-243
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• 2012

This paper is concerned with turbulent flow computations using Large Eddy Simulation (LES) and the flow interaction of vortex shedding in a cylindrical duct flow driven by mass blowing through the wall. The purpose is to analyze non-linear combustion characteristics in the presence of vortex shedding generated in a hybrid rocket motor. Experimental studies have shown sudden changes in pressure (referred as a DC-shift), which depend on the strength of vortex strength of incoming flow. The combustion instability because of a sudden change in pressure fluctuations is mainly related with the interaction between vortex shedding. Therefore LES computation on a duct with injected normal blowing was performed to simulate the turbulent flow interactions with the behaviors of vortices and vortex structures along the injected wall.

• Journal of Life Science
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• v.20 no.5
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• pp.639-643
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• 2010

Sudden deaths have occurred in feedlot cattle with marked necro-hemorrhagic enteritis of the jejunum, ileum and colon. Suckling beef calves are the most frequently affected. Over-consumption of large amounts of milk, inadequate colostrum intake, chilling and stress are conducive to the development of enterotoxemia. Enterotoxemia caused by Clostridium perfringens type D mostly occurs following a sudden change of diet, particularly to feeds made richer in order to grow the cattle to market weight in feedlots. During July 2006, sudden deaths of cattle occurred in the Youngcheon regional area of Gyeongbuk province. There were no significant clinical signs except anorexia, depression, intermittent diarrhea and mild respiratory failure. Histological findings revealed a prominent intranuclear inclusion as well as infiltration of the globular leukocytes in various organs including the heart, kidneys, liver, spleen and lymph nodes. Spleen and lymphatic tissues showed lymphatic necrosis and a starry sky appearance. In the submucosa of the small intestines, basophilic aggregation was detected with massive infiltration of the globular leukocytes and eosinophils. Gram staining for the tissue sections containing inclusions of the small intestines revealed a positive histochemical reaction. Taken together, we suggest that Clostridium perfringens type D-induced enterotoxemia is determined to be the cause of sudden death of feedlot cattle.

• Proceedings of the KIPE Conference
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• 2008.10a
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• pp.48-50
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• 2008

A wind power system with squirrel-cage induction generator has irregular change of output power according to the sudden change of wind speed. This paper describes the development of a active and reactive power compensator, which is composed of a 3-phase inverter and a bidirectional DC/DC converter with super-capacitor. The operational characteristic was analyzed through simulations with PSCAD/EMTDC and experimental works with a scaled model. The developed system can continuously compensate the active power change with energy storage and the reactive power change with 3-phase inverter.

• Korean Institute of Interior Design Journal
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• v.27 no.3
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• pp.136-144
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• 2018

The purpose of this study is to examined the unconscious response of the pupil in the observation toward the image in the eye-tracking experiments that target on a large complex cultural space. Twenty-five men participated in this experiment and the observation data were analyzed in seconds per minute on watching time. It could examine the unconscious response of information searching in the change of pupil size in the process of observing the space. The results could be defined as following several points. First, it was possible to outline the unconscious response characteristics of pupil by analyzing sudden changes in pupil size as total, cumulative, and individual. The response characteristics using frequency and time can be utilized as the analytical method to examine the degree of interest of spatial components according to the purpose of analysis in the future. Second, according to the over ${\pm}5%$ of cumulative variation rate on the pupil size change, during in the 60 seconds, the continuous pupil dilation was used 25.2 seconds in 8.8 rounds and the pupil reduction was used 18.0 seconds in 7.0 rounds. Third, when the variation rate of ${\pm}5%$ or more was regarded as the sudden changes on pupil size by individual variation, the pupil dilation was 7.2 rounds of 8.6 seconds and pupil reduction was 6.0 seconds in 5.0 rounds. This means that the pupil increases 9.3% in one expansion and decreases -8.5% in the reduction process. As regarding pupil changes as cumulative rate, it appeared high change rate on pupil reduction but it became higher on pupil dilation in individual.