• Korean Journal of Construction Engineering and Management
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• v.12 no.6
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• pp.120-129
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• 2011

An installation of the construction lift has a few limitations by many constrains and these have influences on labor productivity, that can be changed by vertical-transportation management. In the super-tall building construction, a management of construction lift operation is one of the most important factor, but existing methodologies depend on skilled practitioners' experiences. And it is true that the expertise resulted by the experiences does not transfer to the next generation. This study is a part of lifting-management simulation development which aims at the optimal construction lift management. A proposed algorithm is focus on lifting time calculation considering an acceleration capability. This research evaluates the result accuracy using comparative analysis on simulation result and field measuring time.

• 한국전산유체공학회:학술대회논문집
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• 2007.10a
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• pp.264-271
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• 2007

The flow simulations around ducted-prop of tilt-duct aircraft were conducted in this study. For the investigation of aerodynamic characteristics of various configurations of duct, the axisymmetric flow calculation method combined with actuator disk model for prop were used. The rapid two-dimensional calculation and fast grid generation enable aerodynamic analysis for various duct configurations in a very short time and anticipated to active role in optimal configuration design of duct exposed to various flight modes. For the case of angle of attack or tilt angle, the three dimensional flow calculation is conducted using the three dimensional grid simply generated by just revolving the axisymmetric grid around center axis. Through the three dimensional calculation around duct, the aerodynamic effectiveness of duct as a lifting surface in airplane mode was investigated. The flow calculations around the control vane (wing) installed in the rear section of duct were conducted The aerodynamic data of wing were compared with the data of the ducts to evaluate the aerodynamic effectiveness of ducts.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.5C
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• pp.344-354
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• 2005

In this paper, we proposed a new lifting architecture for JPEG2000 and implemented to ASIC. We proposed a new cell to execute unit calculation of lifting using the property of lifting which is the repetitious arithmetic with same structure, and then recomposed the whole lifting by expanding it. After the operational sequence of lifting arithmetic was analyzed in detail and the causality was imposed for implementation to hardware, the unit cell was optimized. A new lifting kernel was organized by expanding simply the unit cell, and a lifting processor was implemented for Motion JPEG2000 using it. The implemented lifting kernel can accommodate the tile size of $1024{\times}1024$, and support both lossy compression using the (9,7) filter and lossless compression using (5,3) filter. Also, it has the same output rate as input rate, and can continuously output the wavelet coefficients of 4 types(LL, LH, HL, HH) at the same time. The implemented lifting processor completed a course of ASIC using $0.35{\mu}m$ CMOS library of SAMSUNG. It occupied about 90,000 gates, and stably operated in about 150MHz though difference from the used macro cell for the multiplier. Finally, the improved operated in about 150MHz though difference from the used macro cell for the multiplier. Finally, the performance can be identified in comparison with the previous researches and commercial IPs.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.7C
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• pp.647-657
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• 2005

In this paper, we proposed a new lifting architecture for JPEG2000 and implemented to ASIC. We proposed a new cell to execute unit calculation of lifting using the property of lifting which is the repetitious arithmetic with same structure, and then recomposed the whole lifting by expanding it. After the operational sequence of lifting arithmetic was analyzed in detail and the causality was imposed for implementation to hardware, the unit cell was optimized. A new lifting kernel was organized by expanding simply the unit cell, and a lifting processor was implemented for Motion JPEG2000 using it. The implemented lifting kernel can accommodate the tile size of 1024$\times$1024, and support both lossy compression using the (9,7) filter and lossless compression using (5,3) filter. Also, it has the same output rate as input rate, and can continuously output the wavelet coefficients of 4 types(LL, LH, HL, HH) at the same time. The implemented lifting processor completed a course of ASIC using 0.35$\mu$m CMOS library of SAMSUNG. It occupied about 90,000 gates, and stably operated in about 150MHz though difference from the used macro cell for the multiplier. Finally, the improved operated in about 150MHz though difference from the used macro cell for the multiplier. Finally, the performance can be identified in comparison with the previous researches and commercial IPs.

• Journal of the Society of Naval Architects of Korea
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• v.52 no.5
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• pp.387-394
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• 2015

Before salvaging a wrecked ship, the physics-based simulation is needed to predict lifting force before real operation by floating crane or barge. Procedures affecting lifting force for the salvage can be divided into three stages. At the first stage, the bottom breakout force for the wrecked ship to escape from seabed sediment should be calculated. At the second step, the current force acting on the wrecked ship while lifting from the seabed to near sea surface should be considered. Finally, buoyancy change near at the sea surface when the wrecked ship start to escape from the water should be considered. In the previous studies, only the breakout force at the first stage was calculated based on simple assumption of embedment depth and contact area of the wrecked ship. Therefore, we develop a program for salvage simulation including whole stages. It is composed of four modules such as the equations of motion, time integration, force calculation, and visualization. As a result, it is applied to simulate lifting the wrecked ship according to various environmental loads including seabed sediments.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.42 no.4 s.334
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• pp.19-28
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• 2005

In this paper, we proposed a parallel fast 2-D discrete wavelet transform hardware architecture based on lifting scheme. The proposed architecture improved the 2-D processing speed, and reduced internal memory buffer size. The previous lifting scheme based parallel 2-D wavelet transform architectures were consisted with row direction and column direction modules, which were pair of prediction and update filter module. In 2-D wavelet transform, column direction processing used the row direction results, which were not generated in column direction order but in row direction order, so most hardware architecture need internal buffer memory. The proposed architecture focused on the reducing of the internal memory buffer size and the total calculation time. Reducing the total calculation time, we proposed a 4-way data flow scheduling and memory based parallel hardware architecture. The 4-way data flow scheduling can increase the row direction parallel performance, and reduced the initial latency of starting of the row direction calculation. In this hardware architecture, the internal buffer memory didn't used to store the results of the row direction calculation, while it contained intermediate values of column direction calculation. This method is very effective in column direction processing, because the input data of column direction were not generated in column direction order The proposed architecture was implemented with VHDL and Altera Stratix device. The implementation results showed overall calculation time reduced from $N^2/2+\alpha$ to $N^2/4+\beta$, and internal buffer memory size reduced by around $50\%$ of previous works.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.39 no.9
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• pp.816-822
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• 2011

In this study, a program has been coded to evaluate propeller thrust rapidly following the effects of propeller shapes and the environmental facts. At this time, Semi-infinite Helical Vortices model is used to predict the induction factor which is introduced by Kawada. This program is based on Wrench's Propeller lifting line theory, and it can predict aerodynamic coefficients such as thrust, power, and efficiency. First of all, this program is compared with test results of NACA reports to verify of the reliability. Secondly, subsonic wind tunnel test has been performed following variations of propeller's rpm and inflow velocities.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37A no.11
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• pp.993-1000
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• 2012

In this research, we proposed an efficient VLSI architecture of the lifting-based 2D DWT (Discrete Wavelet Transform) filter with 100% hardware utilization. The (9,7) filter structure has been applied and extendable to the filter length. We proposed a new block-based scheduling that computes the DWT for the lower levels on an "as-early-as-possible" basis, which means that the calculation for the lower level will start as soon as the data is ready. Since the proposed 2D DWT computes the outputs of all levels by one row-based scan, the intermediate results for other resolution levels should be kept in storage such as the Data Format Converter (DFC) and the Delay Control Unit (DCU) until they are used. When the size of input image is $N{\times}N$ and m is the filter length, the required storage for the proposed architecture is about 2mN. Since the proposed architecture processes the 2D DWT in horizontal and vertical directions at the same time with 4 input data, the total period for 2D DWT is $N^2(1-2^{-2J})/3$.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.38 no.11
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• pp.1075-1080
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• 2010

For the aeroelastic analysis of a wing with friction damping, coupled time integration method was used to obtain time responses in the subsonic and transonic regions. To take into account aerodynamic nonlinearity induced by shock wave on the lifting surface, transonic small disturbance equation with in-phase periodic boundary condition was used for unsteady aerodynamic calculation. For 2-DOF airfoil system with displace-dependent friction dampers, the effects of normal load slope and Mach number on flutter boundary were investigated.

• Journal of computational fluids engineering
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• v.15 no.2
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• pp.21-27
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• 2010

Immersed boundary lattice Boltzmann method (IBLBM) has been applied to simulate a turbulent flow over circular cylinder in a flow field effectively. Although IBLBM is very effective method to simulate the flow over a complex shape of obstacle in the flow field regardless of the constructed grids in the calculation domain, the results, however, become numerically unstable in high reynolds number flow. The most effective suggestion to archive the numerical stability in high Reynolds number flow is applying the multiple relaxation time (MRT) model instead of single relaxation time(SRT) model in the collision term of lattice Boltzmann equation. In the research MRT model for IBLBM was introduced and comparing the numerical results obtained by applying SRT and MRT. The hydraulic characteristic of cylinder in a flow field between two parallel plate at the range of $Re{\leqq}2000$represented and it is also compared the drag and lifting coefficients of the cylinder calculated by IBLBM with SRT and MRT model.