• International Journal of Aeronautical and Space Sciences
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• v.15 no.3
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• pp.281-292
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• 2014

We propose a novel cooperative guidance law design method based on the finite time disturbance observer (FTDO) for multiple near space interceptors (NSIs) with impact time control. Initially, we construct a cooperative guidance model with head pursuit, and employ the FTDO to estimate the system disturbance caused by target maneuvering. We subsequently separate the cooperative guidance process into two stages, and develop the normal acceleration command based on the super-twisting algorithm (STA) and disturbance estimated value, to ensure the convergence of the relative distance. Then, we also design the acceleration command along the line-of-sight (LOS), based on the nonsingular fast terminal sliding mode (NFTSM) control, to ensure that all the NSIs simultaneously hit the target. Furthermore, we prove the stability of the closed-loop guidance system, based on the Lyapunov theory. Finally, our simulation results of a three-to-one interception scenario show that the proposed cooperative guidance scheme makes all the NSIs hit the target at the same time.

• The korean journal of orthodontics
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• v.23 no.1 s.40
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• pp.57-74
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• 1993

Anterior crossbite is a common malocclusion in the early deciduous dentition. Even today, many these malocclusion patients are not treated until the mixed or permanent dentition. And the purpose here is to emphasize the need for early diagnosis and possible treatment for these anterior crossbite malocclusions and their associated facial patterns. Case histories of 4 patients selected from the author's practice are presented. Different methods of treatment are evaluated. Some improvement was achieved in all patients from an early interceptive regimen, although ultimately corrective orthodontic treatment may still be needed in some. It is concluded that early interception of deciduous anterior crossbite malocclusion should by attempted in patients ; there should be no delemma in reaching such a decision. And it is essential for diagnosis and treatment to determine exact variations in growth when some appliance are used, it is recommended that growth-related records be made as early as possible.

• International Journal of Reliability and Applications
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• v.12 no.2
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• pp.79-94
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• 2011

Redundancy-reliability allocation problems in multi-stage series-parallel systems are addressed in this study. Fuzzy programming techniques are proposed for finding satisfactory solutions. First, a multi-objective programming model is formulated for simultaneously maximizing system reliability and minimizing system total cost. Due to the nature of uncertainty in the problem, the fuzzy set theory and technique are used to convert the deterministic multi-objective programming model into a fuzzy nonlinear programming problem. A heuristic method is developed to get satisfactory solutions for the fuzzy nonlinear programming problem. A Pareto optimal solution is found with maximal degree of satisfaction from the interception area of fuzzy sets. A case study that is related to the electronic control unit installed on aircraft engine over-speed protection system is used to implement the developed approach. Results suggest that the developed fuzzy multi-objective programming model can effectively resolve the fuzzy and uncertain problem when design goals and constraints are not clearly confirmed at the initial conceptual design phase.

• The Journal of the Korean dental association
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• v.22 no.12 s.187
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• pp.1067-1073
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• 1984

In the treatment of functional orthodontic problems, timing is not an issue. All orthodontists start as soon as the condition is recognized. However, there is an active dialogue concerning treatment timing for structure problems. The major points in contention center around the operator's ability is to control the growth of the facial bones and to maintain post-treatment tooth position through the maturation period (especially when this position was gained by techniques involving arch expansion or distal driving of posterior segments). Factors taken into account to determine the best time of orthodontic treatment include diagnosis, interception, growth rate, patient cooperation, eruptive state and treatment period. With those exceptions of all functional problems, mild dental discrepancies and skeletal deficiencies with a predictably excellent growth potential (early treatment), the period immediately following the eruption of the permanent second molars is the period during which most orthodontic treatment should be initiated. At this time the full volume of tooth substances is present, the individual growth pattern in well established, there are sufficient teeth to receive nearly any type of appliances and the patient can easily tolerate the wearing of appliances.

• Journal of the Korean housing association
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• v.11 no.2
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• pp.117-127
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• 2000

As urbanization proceeds and therefore impervious surface coverage increases, the amount of runoff goes up and the hydrological cycle is also changed. The surface retention and interception of precipitation in the urban area are reduced because the surface area is now slick and solid. Increasing runoff in building areas of the city causes flood damage, water pollution, reduction of ground water recharge, and the other environmental problems. This paper investigates various techniques of increasing rates in a site development performed by Berlin. The techniques offered in this paper improve sit water balance, and thus keep the site ecosystem much healthier.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.52 no.6
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• pp.372-377
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• 2003

Many of modem radars use modulated pulse repetition intervals for the purpose of anti-aliasing and ECCM. The interception, analysis and identification of radar signals is a major function of a radar intercept receiver. In this paper, we discuss the identification of pulse repetition intervals modulation of radar signals which is one of the major parameters for the analysis of radar. We proposed a new algorithm based on Markov models approach. This approach is shown to be reliable and robust to the missing pulses, as well as to require only relatively few pulse data.

• Proceedings of the KIEE Conference
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• 2002.07a
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• pp.259-261
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• 2002

Recently, according to the spread of semiconductor applied technology like motor speed control contrivance, power conversion installation and so on, harmonic ingredients occurred in switching operation flow into a distribution system and increase voltage distortion of distribution system and bring on obstacles like damage, lowering of capability, false operation and so on of various electrical installation. So, in order to consider a countermeasure to limit occurrence quantity of harmonic source, harmonic interception and others, precision measurement and analysis on voltage, current, power, power factor, the each ingredient of harmonic order, the percentage of total harmonic distortion and so forth are needed. In this paper monitoring system to measure and analyze power quality connected with power harmonics was developed and it's performance is verified by measuring and analyzing three-phase voltage and current of R, S, T in the three-phase and four-wire system using the developed measurement system.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.6 no.1
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• pp.9-15
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• 2012

In this paper, the feasibility of a wheelchair carrier for the disabled own driver is checked kinematically to fit one of current domestic vans by drawings, design. A van with 9 passengers is selected for the modification to attach the wheelchair carrier and test the operation in real situation. The trajectory and motion process are studied to protect from the interception with outside body of van, and the conceptual design is proceeded kinematically. For the detail design, the stress analysis and driving mechanism with power supply must be studied and selected basically.

• Journal of the Korean Ceramic Society
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• v.42 no.10 s.281
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• pp.678-684
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• 2005

Sick house syndrome comes from VOCs that is harmful to health. To reduce VOCs, the cause of sick house syndrome, several materials have been developed and use. One of this materials, VOCs absorption paint was developed. VOCs absorption paint contains ceramic binder and zeolite powder. In the present study, eco-ceramics paint has been successfully fabricated by high-speed mixer using ceramic binder and filler powders. The eco-ceramics paint thus obtained have a deodorization rate with about 95.7$ \%$ and the bacteria decreasing rate is about 99.6$\%$. Moreover, the eco-ceramics paint showed excellent VOCs interception properties due to effect of ceramics layer and zeolite which exist in surface of paint.

• Journal of Environmental Science International
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• v.22 no.5
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• pp.523-531
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• 2013

In this study, a method of simulating ephemeral stream runoff characteristics in Jeju watershed is newly suggested. The process based conceptual-physical scheme is established based on the SWAT-K and applied to Cheonmi-cheon watershed which shows the typical pattern of ephemeral stream runoff characteristics. For the proper simulation of this runoff, the intermediate flow and baseflow are controlled to make downward percolation should be dominant. The result showed that surface runoff simulated by using the modified scheme showed good agreement with observed runoff data. In addition, it was found that the estimated runoff directly affected the groundwater recharge rate. This conceptual model should be continuously progressed including rainfall interception, spatially estimated evapotranspiration and so forth for the reasonable simulation of the hydrologic characteristics in Jeju island.