• 한국정보통신설비학회:학술대회논문집
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• 2009.08a
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• pp.25-27
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• 2009

In this paper, a sensor network system for providing intelligent home network services is suggested. It steadily collects biological data of resident people and automatically detects emergency situations LEID(Lighting Embedded Information Device) system are the most essential component of the sensor network. They embed sensor network technology into lightening devices which are indispensable most living spaces. To verify practicality of the proposed intelligent home network service system, a prototypical system is realized in the Smart Home Industrialization Support Center at Kookmin University, and is tested within many practical circumstances.

• Proceedings of the Korean Society For Composite Materials Conference
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• 1999.11a
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• pp.101-106
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• 1999

Fiber reinforced plastic composites is widely used to make be lightening of aircraft and automotive owing to having high specific strength and specific modulus. And it is very important to know a charge shape in order to have good products in the compression molding. In particular, the product such as a bumper beam is composed of the random and unidirectional composite mats. Its deformation and charge shape are very different by stack type of random and unidirectional mats. In this paper, the characteristics of flow fronts such as a bulging phenomenon for step-type random/unidirectional composite mats and slip parameters are studied numerically. And the effects of viscosity ratio and stack type on the mold filling parameters are also discussed.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.983-987
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• 2003

Vibration causes noise and makes structure unstable. Especially, due to the effort of lightening, deformation of flexible structure is increased in its shape. Just a little disturbance causes vibration and low damping ratio causes residual vibration lasts long time. In this paper, by using a neuro-controller, which is one of the algorithm of adaptive control. we performed adaptive control of flexible cantilever plate and opened box structure with piezoelectric materials. The proposed adaptive vibration control algorithm, a neuro-controller, is proved in its effectiveness by applying to a opened box structure. The neuro-controller was implemented with DSP, and the real-time adaptive vibration control experiment results confirm that neuro-controller is reliable.

• Journal of Advanced Marine Engineering and Technology
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• v.36 no.4
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• pp.467-475
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• 2012

In this paper, a technical method of reducing torque load of exoskeleton device, with using of a gravity compensator based on a torsion bar, for human leg joints, is proposed. Design and structure analyses and also performance test were performed to estimate and to measure the characteristics of the torsion bar. On the basis of design and structure analysis, a new light and compact exoskeleton device has been developed. For the purpose of lightening and optimizing thickness of the links, FEM analysis has been performed.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.21 no.5
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• pp.830-835
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• 2012

A research for application of LDSMC(Low Density Sheet Molding Compound) composite is in progress for lightening the weight. This paper has performed fatigue test and simulation of external panel for Korean commercial vehicle. Before the fatigue test, static test was carried out. From the test, the structural safety was investigated using Goodman diagram. After the static test performance, the fatigue test was conducted at a range of load frequency 5Hz, a stress ratio(R) of 0.05 and an endurance limit of $10^6$ to obtain the S-N curve. The S-N curve is applied to the fatigue analysis of the external panel assembly. The result of FEM analysis was in accord with the experimental result within 83% confidence. It showed that the process to set up the safety range of allowable error is required in process of the design and simulation verification.

• Journal of Aerospace System Engineering
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• v.10 no.1
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• pp.118-126
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• 2016

North Korea has continued developing ballistic missiles with various ranges. Even through the recent launch long-range missiles, it can be inferred that North Korea's Missile technology has reached a level where it can even threaten the US. moreover, through the three times nuclear tests, North Korea is known to have succeeded at gaining 10~20KT of explosive power as well as the minimization and lightening of nuclear warhead. Considering the short length of war zone in Korean peninsula and the possibility of nuclear equipment, if be the most severe threat across the whole peninsula. Since the midcourse phase flight takes the longest time, ROK should establish the ability to intercept at this middle phase. From this perspective, this paper describes mission effect of a sea-based BMD system through empirical threat and flight characteristic analysis using MIT model that was not suggested in original research.

• Journal of Power System Engineering
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• v.19 no.4
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• pp.76-81
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• 2015

The production of electricity from wind energy is noticed as economic power generation system in the natural resource. Lately, since lots of wind turbine have installed globally, the accidents have increased gradually. In this paper, we classified domestic information for 10 years, information of new energy and industrial technology development organization(NEDO) for 4years and caithness windfarms information forum(CWIF) for 15 years according to part and cause of wind turbine accident. We found that the main causes of accidents are storm, lightening and carelessness. The results of classifying and analyzing the informations, should be used to take measures on the accident prevention of wind turbine.

• Journal of Power System Engineering
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• v.19 no.3
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• pp.36-41
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• 2015

The true north-finding equipment utilizing gyro sensor is used for INS(Inertial Navigation System) and has an increasing preference for gyro compass system due to compact size, lightening, low power and price. The purpose of this experiment is to research gyro compass system providing high performance in the field of manned or unmanned gyro compass system which proposes the accuracy of 1% utilizing experimented equipment at true north of the earth. Unlike the conventional system, the proposed gyro sensor system indicates to be applied in the various and specific equipment using multiple technique and method.

• Proceedings of the Korea Concrete Institute Conference
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• 1997.10a
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• pp.223-228
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• 1997

In this study, bottom ash, lightweight aggregate, and Expanded Polystyrene was used to lighten the mortar. In order to compensate the reduction of strength caused by lightening, the waste foundry sand produced as solid waste was substituted for fine aggregate. As the device of reducing the ratio of absorption, the procedure of mixture was altered to check the effectiveness of surface coating of porous lightweight aggregate. It was observed over 170kg/$\textrm{cm}^2$ compressive strength at gravity about 1.3, an over 380kg/$\textrm{cm}^2$ at gravity about 1.7. the maximum strength was occurred when 30% of fine aggregate was replaced was replaced with waste foundry sand, and the ratio of absorption was decreased over 10% by changing the procedure of mixture.

• Korean Journal of Child Studies
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• v.15 no.2
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• pp.55-68
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• 1994

A survey analysis of home video games was carried out for 1,018 elementary school children. Children responded to a questionnaire consisting of sociodemographic variables, degree of game participation(frequency and mean time), control behavior(eg. resting during games, lightening interior), and physical symptoms(eg. eyestrain, headache, trembling, paralyses) during and/or after playing games. Statistical analysis was done by frequency, percentile, and chitest. The results showed that many children enjoyed video games frequently and played continually, that few children did control behavior during games. Main variables related to degree of game playing and control behavior were sex, game experience, parent's education, and mother's activity. In particular, the results implied that the level of physical symptoms during and/or after game differed by lighting factors.