• The Journal of the Korea Contents Association
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• v.9 no.2
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• pp.67-75
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• 2009

The growing need for the mobility supportable networks induces the IP-based mobility management protocols. Though HMIPv6 which manages the micro-mobility of mobile nodes using MAPs suggests an effective method for mobility-support for mobile nodes within the domain that is managed by MAP. There is a problem that traffic may be concentrated on MAPs. In this paper, therefore, we proposed a method that can effectively distribute the traffic which is concentrated on a MAP under phased Mobile IPv6. In our proposed method, two or more MAPs are required and classified as an 'Active MAP' or a 'Passive MAP'. In addition, we defined the state of transition events between Active MAP and Passive MAP and the operations among MAPs for load distribution when an overload condition is occurred at some MAPs by traffic congestion. We compared the performance of our proposed method with its phased Mobile IPv6 to prove the propriety of our proposed method. As a result, we showed that our proposed method can provide an enhanced performance by about 12 percentages in view of packet throughput at the node.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.20 no.5
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• pp.85-95
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• 2021

Structure design sensitivity was evaluated using the orthogonal array experimental method for passive-type deck support frame (DSF) developed for float-over installation of the offshore plant. Moreover, approximation characteristics were also reviewed based on various meta-models. The minimum weight design of the DSF is significantly important for securing both maneuvering performance and buoyancy of a ship equipped with the DSF and guaranteeing structural design safety. The performance strength of the passive type DSF was evaluated through structure analysis based on the finite element method. The thickness of main structure members was applied to design factors, and output responses were considered structure weight and strength performances. Quantitative effects on the output responses for each design factor were evaluated using the orthogonal array experimental method and analysis of variance. The optimum design case was also identified from the orthogonal array experiment results. Various meta-models, such as Chebyshev orthogonal polynomial, Kriging, response surface method, and radial basis function-based neural network, were generated from the orthogonal array experiment results. The results of the orthogonal array experiment were validated using the meta-modeling results. It was found that the radial basis function-based neural network among the meta-models could approximate the design space of the passive type DSF with the highest accuracy.

• Journal of Korean Society for Atmospheric Environment
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• v.18 no.5
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• pp.383-391
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• 2002

Six types of ozone passive samplers were fabricated with three different filter substrates and two colorants, and tested for their feasibility on atmospheric monitoring. These passive samplers are based on a colorant which fades (indigo carmine and ChromAir (K&M environmental Inc.)) or produces color (mixture of 3-methyl-2-benzothiazolinone acetone azine and 2-phenylphenol colorant) upon reaction with ozone, whose concentration can be determined by reflectance measurement of the color change. Three filters, namely Whatman No.1 paper, SG81 chromatography paper and Silica Gel coated on polyester (TLC Plates), were prepared and coated with two colorants. The response of these passive samplers in ozone chamber were tested and compared with ChromAir (K&M environmental Inc.) passive sampler. The response of Silica Gel filter impregnated with indigo carmine was the best at the constant concentration exposure.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.11a
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• pp.118-119
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• 2006

현재의 소자간 연결을 위해 사용되는 금속배선의 한계로 인해 보다 고속/대용량의 광연결(Optical Interconnection)이 크게 각광받고 있다. 본 논문에서는 FEM 시뮬레이션(Finite Element Method Simulation)을 통해 온도변화에 따른 기판에서의 온도분포를 살펴보고, 열응력 분포와 열응력 집중에 의한 기판의 변형으로 인한 문제를 연구하였다. 이를 통해 향후 Optical Passive Component 설계시 Optical Passive Component 변형의 원인이 될 수 있는 열원들의 배치를 최적화 시키고 기판의 취약부운을 보강하여 우수한 성능의 Optical Passive Component 제작을 목표로 하고 있다.

• Journal of the Optical Society of Korea
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• v.15 no.4
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• pp.357-361
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• 2011

Photon-counting sensing is a widely used technique for low-light-level imaging applications. This paper proposes a distance information extraction method with photon-counting passive sensing under low-lightlevel conditions. The photo-counting passive sensing combined with integral imaging generates a photon-limited elemental image array. Maximum-likelihood estimation (MLE) is used to reconstruct the photon-limited image at certain depth levels. The distance information is extracted at the depth level that minimizes the sum of the standard deviation of the corresponding photo-events in the elemental image array. Experimental and simulation results confirm that the proposed method can extract the distance information of the object under low-light-level conditions.

• Transactions of the Korean Society of Automotive Engineers
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• v.12 no.4
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• pp.129-138
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• 2004

In this paper, we propose a method to apply a decentralized control algorithm for passive velocity field control using virtual flywheel system to cooperative 3-wheeled mobile robots, and these subsystem are under nonholonomic constraints. The considered robotic systems convey a common rigid object in a horizontal plain. Moreover we will proof the passivity and robustness for cooperative mobile robotic systems with decentralized passive velocity field control. Finally, The effectiveness of proposed control algorithm is examined by numerical simulation for cooperation tasks with 3-wheeled mobile robot systems.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.55 no.8
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• pp.378-385
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• 2006

In this study, a method measuring signal propagation direction in human body was developed by using passive electrical properties of the body. The measured method of the signal propagation direction is to apply basic characteristic of electricity to the human body; when a voltage is set to a conducted medium, according to the polarity of the conducted voltage, the voltage rising or drop is generated. And using this concept, it is able to estimate the direction of electrical signal on the human body. The passive electrical properties were measured and the direction of signal propagation was estimated on the followings; between the flexor carpi radialis, between arms, between legs, between an arm and a leg, between the cervical vertebra and the upper limb, between the sacral vertebra and the leg, between the cervical vertebra and the tendon of triceps brachii, and between the sacral vertebra and the calcaneal tendon. As the result of experiments, the passive electrical properties were increased from l[Hz] to 50[kHz] of the inputted frequencies and showed at saturating tendency after that. And also, the estimated signal propagation directions using the developed method in this study agreed with the expected directions exactly at each part of the human body.

• Journal of Preventive Medicine and Public Health
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• v.33 no.1
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• pp.91-98
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• 2000

Objectives : This study is to evaluate the awareness, attitude, practice and the countermeasures against passive smoking in Korean adults. Methods : By self-administered questionnaires, we assessed the knowledge, attitude, behavior for passive smoking and the countermeasure for reduction of it's harmful effects in 289 men and 238 women. Results : The subjects that have heard about passive smoking were 96.8% in total and well known were 26.4% of current smoker, 56.6% of ex-smoker, and 14.8% of non-smoker(p=0.001). The irritative symptom from passive smoking was the most frequent in non-smokers and the most common place where exposed to passive smoking was public place. For attitude against passive smoking in 'no smoking allowed area', ex-smokers were the most active to recommend to stop smoking. And for opinion about establishment of 'no smoking allowed area', the restriction by law was the best acceptable method in smokers, exsmokers, and nonsmokers. In marking of 'no smoking allowed area', 69.9% of smokers answered no smoking, but in non-marking area only 6.3% stop smoking. When smokers were recommended to stop smoking, the more subjects stop smoking with good feeling in marking area, but the less in non-marking area. The factor associated the high awareness of passive smoking were aged(OR=1.07, 1.03-1.12), men(OR=4.34, 2.32-8.46). The persons who have known well about passive smoking had good attitude and behavior to prevent of harmful effect of passive smoking. Conclusions : This study suggested that education program would be necessary to reduce the passive smoking.

• Journal of Institute of Control, Robotics and Systems
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• v.19 no.2
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• pp.102-106
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• 2013

A cooperative navigation method for cooperative flight of UAVs is proposed. The commonly used navigation method for UAVs is based on GNSS measurements. However, when it is not available by jamming or other causes, an alternative method is needed. In this paper, it is shown that UAVs equipped with inertial sensors, passive sensor and wireless communication link can perform accurate navigation through sharing information with each other. Firstly, the appropriate roles for sensors and wireless communication link are assigned. Secondly, a filter to perform navigation cooperative is constructed. Finally, the boundedness of estimation error of the filter under small initial estimation error is analyzed. The simulation results show that the proposed method can reduce navigation errors effectively.

• Advances in aircraft and spacecraft science
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• v.3 no.3
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• pp.299-315
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• 2016

In this work, a strategy for passive vibration control of periodic structures is proposed which involves adding a periodic array of simple resonant devices for creating band gaps. It is shown that such band gaps can be generated at low frequencies as opposed to the well known Bragg scattering effects when the wavelengths have to meet the length of the elementary cell of a periodic structure. For computational purposes, the wave finite element (WFE) method is investigated, which provides a straightforward and fast numerical means for identifying band gaps through the analysis of dispersion curves. Also, the WFE method constitutes an efficient and fast numerical means for analyzing the impact of band gaps in the attenuation of the frequency response functions of periodic structures. In order to highlight the relevance of the proposed approach, numerical experiments are carried out on a 1D academic rod and a 3D aircraft fuselage-like structure.