• Journal of the Society of Disaster Information
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• v.13 no.3
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• pp.358-365
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• 2017

As the damage caused by disasters increases rapidly around the world, it is necessary to develop the technology for equipment to reduce human injury. Therefore in the support of fire safety and 119 rescue and rescue technology research and development project, in the "Development of a power assist device for a fireman to rescue humans(2015 ~ 2018)" for life saving restoration, we are developing equipment that satisfies the lifting performance considering the disaster environment and the disaster response scenario(Amount of load over 100 kg, height of over 1 m, height over middle 60 cm, speed over 0.2 m/s). In this study, we propose a lifting performance and environmental test method to evaluate the usefulness of the power-assisted device and analyze and verify detailed specifications of the device through dynamics analysis of the lifting performance test. This study suggests that the proposed test method can be applied practically to evaluate whether a stable performance of a power-assisted device is achieved.

• Journal of Ocean Engineering and Technology
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• v.11 no.4
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• pp.249-261
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• 1997

A basic study on the lifting lug design has performed through the rational and systematic process. In order to evaluate the proper design-load distribution around lug eye investigation of contact force between lifting lug and shackle pin is performed using non-linear parametric analysis idealized by gap element models. Gap element modeling and nonlinear analysis procedures are illustrated and discussed based on MSC/NASTRAN. Some analysis and design guides are suggested through the consideration of several important effects such as stress distribution pattern, circumferential contact force distribution along the lug eye face, loading share rate between lug main plate and doubler, effect of loading direction, relation between applied force and deflection and size effect of shackle pin radius. Additionally optimum design studies are performed and general trends according to the variation of design parameters are suggested.

• Proceedings of the IEEK Conference
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• 2003.07e
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• pp.1731-1734
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• 2003

In this paper, we describe an approach for image denoising using the lifting construction, with the spatial adaptive wavelet transform. The adaptive lifting scheme is implemented in spatial domain to be adjusted thresholds to reduce noise. In this approach we represent adaptive characteristics of biorthogonal wavelets for choosing predictors effectively. Predict filter is changed from sample to sample according to local signal features with their vanishing moments. We in this approach have implemented and applied to image denoising by finding a relevant minimax threshold. Experimental results show that the adaptive method of denoising process is compared with existing ones, such as non-adaptive wavelet, CRF(13, 7) and SWE(13, 7) wavelets used by JPEG2000.

• Journal of Biomedical Engineering Research
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• v.32 no.4
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• pp.328-335
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• 2011

For human factor engineering and wearable robot design, the quantitative assessment of physical workload is needed. Through measuring the surface EMG (sEMG) and analysis, the physical workload in overhead lifting posture is presented in quantitative manner. By normalizing sEMG activities with maximal voluntary contraction (MVC), the inter-subject variability is reduced. In all muscles, %MVC increased as the weight of lifting object increases. In anterior deltoid muscle, the %MVC was 3-4 times higher than the other muscles which imply that this muscle performs the major role in the overhead lifting posture. In fatigue analysis, %MVC and the mean frequency in muscle of anterior deltoid changed markedly when compared with other muscles. Through the suggested procedures and analysis, the physical workload for a specific posture can be represented in quantitative way but the clinical meaning for the value should be investigated further.

• Journal of Ship and Ocean Technology
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• v.7 no.3
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• pp.34-55
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• 2003

Explicit Kutta condition approximation, proved useful in existing time-domain solver of the unsteady propeller problem, requires a specified functional behavior of the vorticity in space near the trailing edge. In this paper, the strength of the discrete vortices is controlled to have a specified behavior in space in the frequency domain approach. A new formulation is introduced and is implemented for analysis of a lifting surface of a rectangular planform. Sample computations carried out according to the new formulation compares well with that of existing unsteady lifting problem in the time domain.

• Proceeding of EDISON Challenge
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• 2016.11a
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• pp.101-105
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• 2016

Prandtl's Lifting-line theory is the classical theory of calculating aerodynamic properties. Though it is classical method, it predicts the aerodynamic properties well. By lifting-line theory, high aspect ratio is critical factor to decrease induced drag. And 'elliptic-similar' wing also makes the minimum induced drag. But due to the problem of manufacturing, tapered wing is preferred and have been utilized. In this Paper, by using Edison CFD, verifying the classical lifting-line theory. To consider induced drag only, using Euler equation as governing equation instead of full Navier-Stokes equation. Refer to the theory, optimum taper ratio which makes the minimum induced drag is 0.3. Utilizing the CFD results, plotting oswald factor over various taper ratio and investigating whether the consequences are valid or not. As a result, solving Euler equation by EDISON CFD cannot guarantee the theoretical values because it is hard to set the proper grid to solve. Results are divided into two cases. One is the values are decreased gradually and another seems to following tendency, but values are all negative number.

• Bulletin of the Society of Naval Architects of Korea
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• v.27 no.4
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• pp.27-31
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• 1990

To calculate the lift of a thin lifting surface like the ship-rudder, it is popular to replace the lifting surface by a series of vortices. Two methods, which are vortex lattice method and mode function method, are frequently used to distribute the vortices on the lifting surface. In this paper, the intermediate way of two mentioned calculation method is carried out to exploit the merits of them. The basic concept of this method is to divide the lifting surface with several strips in span-wise and replace vortices to the chord-wise at each strips. A horn type semi-balanced rudder is chosen for the real method, and the validity of the proposed calculation is pursued by the open water test of the same rudder. Finall, this method is applied to the calculation of the interference between the two homogenous rudders siting parallel to the free stream.

• Journal of Institute of Control, Robotics and Systems
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• v.13 no.11
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• pp.1040-1047
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• 2007

This paper presents ripple-free method that can occur in multirate controller design. The conventional multirate input controller has the problem that the ripple occurs in track-following because of chattering phenomenon in control input signal. In order to resolve the problem of rippling, it was proposed to eliminate the ripple phenomenon using feedforward compensator. This paper makes explains problems in conventional ripple-tree multirate controller and introduces a multirate controller design method applying lifting technique based on current estimators in condition space. Using the ripple-tree multirate controller, we show that chattering does not occur in the control input signal through applying the final value theorem from the viewpoint of discrete-time transformation. Also, this study proves that the ripple of the proposed controller decreases with the increase of this sampling frequency and, when sampling frequency is fixed, it decreases with the increase of the control input period.

• Journal of The Institute of Information and Telecommunication Facilities Engineering
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• v.5 no.1
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• pp.1-11
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• 2006

Lifting scheme based integer transforms provides very useful properties on the multimedia coding. An integer transform outputs the integer form when the input has integer value. This doesn't produce quantization errors on coding, so integer transforms are adequate to lossless coding, In this paper, we present an integer DCT algorithm which is able to transform audio signal with longer length. Also the proposed method can be easily implemented recursively even though input is long time. We present the method to overcome the poor approximation which is produced by recursive lifting step. And we have applied the proposed integer DCT to lossless audio coding.

• Journal of Information Processing Systems
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• v.14 no.5
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• pp.1293-1300
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• 2018

For the disadvantages of multi-scale geometric analysis methods such as loss of definition and complex selection of rules in image fusion, an improved multi-focus image fusion method is proposed. First, the initial fused image is quickly obtained based on the lifting stationary wavelet transform, and a simple normalized cut is performed on the initial fused image to obtain different segmented regions. Then, the original image is subjected to NSCT transformation and the absolute value of the high frequency component coefficient in each segmented region is calculated. At last, the region with the largest absolute value is selected as the postfusion region, and the fused multi-focus image is obtained by traversing each segment region. Numerical experiments show that the proposed algorithm can not only simplify the selection of fusion rules, but also overcome loss of definition and has validity.