• Proceedings of the Korean Institute of Building Construction Conference
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• 2015.05a
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• pp.211-212
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• 2015

Procurement and lifting scheduling of modules and resources in modular construction, where modules that are manufactured from factory are delivered and assembled on site, is a crucial factor that determines the efficiency of the whole construction. However, previous studies have barely acknowledged the significance of resource procurement process and lifting of modules in modular construction. Therefore, this research aims to derive factors that are in need of improvement for successful implementation of procurement and lifting efficiency, and visualize them according to their importance and performance on improvement through IPA(Important Performance Analysis).

• Journal of Institute of Convergence Technology
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• v.3 no.2
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• pp.57-60
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• 2013

The purpose of this study is to analysis of how to calculate fuel efficiency in major development countries (U.S. and Europe) and energy consumption formular derivation of domestic CNG fuel and prove by vehicle test. The formula of fuel consumption is different in mpg(mile per gallon), l/100km, and km/l each countries. CNG fuel has a significant impact on fuel density, composition, and Hydro-Carbon ratio. So, this study how to measurement and calculation procedures of CNG gaseous fueled vehicle energy consumption rate.

• Journal of the Institute of Convergence Signal Processing
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• v.13 no.3
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• pp.162-165
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• 2012

In this paper, the method of controlling velocity between joining vehicles at the point of bottleneck using information and communications technology of WAVE method based V2V and V2I are proposed for the driving with high fuel efficiency. Using the derived fuel-efficiency comparative analysis model, it was shown that the proposed method's fuel efficiency is better than traffic light method demanding periodically vehicle's stop. Also, this method provides the derivation algorithm for deceleration and acceleration for controlling velocity between vehicles approaching bottleneck area.

• Bulletin of the Korean Chemical Society
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• v.22 no.1
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• pp.46-52
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• 2001

To evaluate the non-ionic polymer, poly(ethylene glycol) (PEG), as a component in cationic copolymers for non-viral gene delivery systems, PEG was coupled to polyethylenimine (PEI). We present the effects of different degrees and shapes of pegylation of PEI on cytotoxicity, water solubility and transfection efficiency. This work reports the synthesis and characterization of a series of cationic copolymers on the basis of the conjugates of PEI with PEG. The modified molecules were significantly less toxic than the original polymer. Moreover, the chemical modification led to enhancement of their solubility. The comparison of pegylated PEIs with different degrees of derivation showed that all the polymers tested reached comparable levels of transgene expression to that of native PEI. As assessed by agarose gel electrophoresis, even highly substituted PEI derivatives were still able to form polyionic complexes with DNA. However, aside from an increase in solubility and retention of the ability to condense DNA, methoxy-PEG-modified PEIs resulted in a significant decrease in the transfection activity of the DNA complexes. In fact, the efficiency of the copolymer was compromised even at a low degree of modification suggesting that the PEG action resulting from its shape is important for efficient gene transfer. The mode of PEG grafting and the degree of modification influenced the transfection efficiency of PEI.

• Journal of the Korean Society for Environmental Technology
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• v.19 no.6
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• pp.543-549
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• 2018

In this study, the treatment efficiency of inorganic membrane according to the flux that blending raw water was investigated at the laboratory level. Based on the results of each blending and flux, we obtained the best efficiency according to each measurement item. The treatment efficiencies were different depending on the raw water and treatment amount of the treated water. Especially, turbidity removal efficiency was high. In the case of $UV_{254}$, the removal efficiency according to the concentration of the raw water and the removal efficiency according to the flux of the treated water showed a maximum of 69 % to minimum of 48 %. In the case of TOC and DOC, the processing efficiency was 22 % and 28 %, respectively, because the organic value of the raw water was low. These results suggest that there is an optimal process to effectively remove contaminants from the inorganic membrane process, and it is necessary to optimize it according to operating conditions.

• Wind and Structures
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• v.31 no.5
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• pp.473-482
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• 2020

The first-order method for estimating the extreme wind pressure on building envelopes with consideration of the directionality of wind speed and wind pressure is improved to enhance its computational efficiency. In this improved method, the result is obtained directly from the empirical distribution of a random selection of annual maximum wind pressure samples generated by a Monte Carlo method, rather than from the previously utilized extreme wind pressure probability distribution. A discussion of the relationship between the first- and full-order methods indicates that when extreme wind pressures in a non-typhoon climate with a high return period are estimated with consideration of directionality, using the relatively simple first-order method instead of the computationally intensive full-order method is reasonable. The validation of this reasonableness is equivalent to validating two assumptions to improve its computational efficiency: 1) The result obtained by the full-order method is conservative when the extreme wind pressure events among different sectors are independent. 2) The result obtained by the first-order method for a high return period is not significantly affected when the extreme wind speeds among the different sectors are assumed to be independent. These two assumptions are validated by examples in different regions and theoretical derivation.

• Journal of Power Electronics
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• v.15 no.1
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• pp.86-95
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• 2015

An active clamp high step-up boost converter with a coupled inductor is proposed in this paper. In the proposed strategy, a coupled inductor is adopted to achieve a high voltage gain. The clamp circuit is included to achieve the zero-voltage-switching (ZVS) condition for both the main and clamp switches. A rectifier composed of a capacitor and a diode is added to reduce the voltage stress of the output rectifier diode. As a result, diodes with a low reverse-recovery time and forward voltage-drop can be utilized. Since the voltage stresses of the main and clamp switches are far below the output voltage, low-voltage-rated MOSFETs can be adopted to reduce conduction losses. Moreover, the reverse-recovery losses of the diodes are reduced due to the inherent leakage inductance of the coupled inductor. Therefore, high efficiency can be expected. Firstly, the derivation of the proposed converter is given and the operation analysis is described. Then, a steady-state performance analysis of the proposed converter is analyzed in detail. Finally, a 250 W prototype is built to verify the analysis. The measured maximum efficiency of the prototype is 95%.

• Nuclear Engineering and Technology
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• v.54 no.1
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• pp.19-29
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• 2022

The 2D/1D method has become the mainstream of the direct transport calculation considering the balance of accuracy and efficiency. However, the 2D/1D method still suffers from stability issues. Recently, a quasi-3D method has been proposed with axial Legendre expansion. Analysis and comparison of the 2D/1D and quasi-3D method is conducted in theory from the equation derivation. Besides, the C5G7 benchmark, the KUCA benchmark and the macro BEAVRS benchmark are calculated to verify the theory comparisons of these two methods with the direct transport code SHARK. All results show that the quasi-3D method has better stability and accuracy than the 2D/1D method with worse efficiency and memory cost. It provides a new option for direct transport calculation with the quasi-3D method.

• Journal of Broadcast Engineering
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• v.13 no.4
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• pp.516-527
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• 2008

This paper introduces a derivation method of both P-SKIP and B-SKIP modes for illumination compensation in the multi-view video coding scheme. In this proposed method, mismatches between IC flag and IC offset in P-SKIP mode are removed, and also computational complexity is far reduced in B-SKIP mode in comparison to a multi-view video coding scheme. In simulation results, proposed method has the almost same coding efficiency in comparison with the referenced coding scheme. However computational complexity in 11m-time decoding process is tremendously reduced, such that the average number of blocks that should be processed in P-SKIP mode is saved in about 7.47%, and the average number of operations per block in B-SKIP mode is saved in about 50.36% and corresponding average decoding time per block is also saved in 46%.

• Journal of Broadcast Engineering
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• v.20 no.4
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• pp.545-556
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• 2015

A HEVC-compatible 3D video coding method (3D-HEVC) has been recently developed as an extension of the high efficiency video coding (HEVC) standard. In order to efficiently deal with the multi-view video plus depth (MVD) format, 3D-HEVC exploits an inter-component prediction which allows the prediction between texture and depth map images in addition to a temporal prediction used in the conventional single layer video coding such as H.264/AVC and HEVC. The performance of the inter-component prediction is normally affected by the accuracy of the disparity vector, and thus it is important to have an accurate disparity vector used for the inter-component prediction. This paper, therefore, introduces a disparity derivation method and inter-component algorithms using the disparity vector for the efficient 3D video coding. Simulation results show that the 3D-HEVC provides higher coding performance compared with the simulcast approach using HEVC and the simple multi-view extension (MH-HEVC).