• Journal of the Korean Institute of Rural Architecture
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• v.26 no.2
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• pp.9-16
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• 2024

In order to achieve carbon neutrality in the architectural field by 2050, this study analyzed the energy impact proportional to CO2 emissions of each technique, such as design methods, the properties of building structures, prefabrication methods, passive houses, and active facilities. In addition, the results were presented quantitatively in terms of carbon reduction, and corresponding housing cases were analyzed. The research method is limited to residential buildings at the Passive House energy level, and carbon reduction techniques and elements in architecture are examined through various literature and materials, and empirical cases are analyzed to determine the specific possibility of realizing carbon reduction in architecture. We want to secure it. Based on these analysis results, it was possible to suggest that it is possible to explore various approaches to carbon reduction in future residential construction. By combining the most efficient techniques according to the energy reduction level or goal setting of the building in question, we expect the possibility of achieving the goal of carbon reduction in the residential sector more realistically.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.9
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• pp.1240-1248
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• 2013

This paper describes a switching-level operation analysis of BTB(Back-To-Back) converter for HVDC(high voltage DC) application based on MMC(modular multi-level converter). A switching-level operation analysis for BTB converter is very important to understand the converter operation in detail and check the voltage and current transients in each components. However, the development of switching-level simulation model for the actual size BTB Converter is very difficult because the MMC normally has more than 150 sub-modules for each arm. So, a switching level simulation model for the 11-level MMC-based BTB converter was developed with PSCAD/EMTDC software, which has 12 sub-modules for the positive arm and another 12 sub-modules for the negative arm. The DC-voltage balance algorithm, the circulating-current reduction algorithm, the harmonic reduction algorithm, and the redundancy operation algorithm were included in this simulation model. The developed simulation model can be utilized to analyze the MMC-based BTB converter for HVDC application in switching level and to develop the protection scheme for the MMC-based BTB converter for HVDC application.

• Horticultural Science & Technology
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• v.31 no.4
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• pp.503-511
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• 2013

The purpose of this study was to evaluate temperature reduction and heat budget of extensive modular green roof planted with Sedum sarmentosum and Zoysia japonica. Plant height and green coverage were measured as plant growth. Temperature, net radiation and evapotranspiration of concrete surface, green roof surface, in-soil and bottom were measured from August 2 to August 3, 2012 (48 hours). On 3 P.M., August 3, 2012, when air temperature was the highest ($34.6^{\circ}C$), concrete surface temperature was highest ($57.5^{\circ}C$), followed by surface temperature of Sedum sarmentosum ($40.1^{\circ}C$) and Zoysia japonica ($38.3^{\circ}C$), which proved temperature reduction effect of green roof. Temperature reduction effect of green roof was also shown inside green roof soil, and bottom of green roof. It was found that Zoysia japonica was more effective in temperature reduction than Sedum sarmentosum. Compared with the case of concrete surface, the highest temperature of green roof surface was observed approximately 2 hours delayed. Plant species, temperature and soil moisture were found to have impact on surface temperature reduction. Plant species, air temperature, soil moisture and green roof surface temperature were found to have impact on temperature reduction in green roof bottom. As results of heat budget analysis, sensible heat was highest on concrete surface and was found to be reduced by green roof. Latent heat flux of Zoysia japonica was higher than that of Sedum sarmentosum, which implied that Zoysia japonica was more effective to improve thermal environment for green roof than Sedum sarmentosum.

• Proceedings of the Korea Institutes of Information Security and Cryptology Conference
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• 1996.11a
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• pp.151-159
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• 1996

본 논문에서는 right-to-left 형태의 멱승 연산에 적합한 고속 모듈라 감소 알고리듬을 제안하고 이를 여러 멱승 방식에 적용했을 경우의 계산 속도 및 메모리 사용효율을 기존의 방식들과 비교하였다. 분석 결과, 기존의 방식보다 고속으로 멱승을 수행할 수 있고 m-ary 방식이나 window 방식에서는 사용 메모리를 줄일 수 있다.

• Proceedings of the KWS Conference
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• 2006.10a
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• pp.152-154
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• 2006

• 제어로봇시스템학회:학술대회논문집
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• 1989.10a
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• pp.230-234
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• 1989

This paper presents the design of a prototype robot and architecture of a distributed control system. The robot, named as KAEROT, has been developed for the purpose of the reduction of personal radiation exposure and the remote maintenance tasks in nuclear facilities. The mobile system with robotic manipulator has been designed to go up and down stairs. For the dextrous handling, this manipulator will be designed as a redundant type to act like a human arm. Manipulator control system is to be extended easily for further usage with a modular architecture to get independency and reliability by minimizing EMI effects.

• Journal of the Korea Institute of Building Construction
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• v.23 no.5
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• pp.527-536
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• 2023

This research embarked on a comprehensive examination of the engineering characteristics of lightweight concrete intended for implementation in rhamen-type modular building walls. The concrete was formulated utilizing bottom ash and coated EPS beads, in accordance with the Korea Construction Standards Center(KCS) 14 20 20 "Lightweight Aggregate Concrete". Our findings articulate that while EPS beads tend to diminish the compressive strength of the lightweight concrete, they concurrently contribute to a notable reduction in unit mass. The porous nature of the bottom ash endows the material with diminished thermal conductivity. Significantly, a mixture containing 50% EPS beads and 50% BA20 aggregates, replacing half of the coarse aggregates, was found to meet the standard specifications.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.43 no.7 s.349
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• pp.115-121
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• 2006

The efficiency of the multiplier largely depends on the representation of finite filed elements such as normal basis, polynomial basis, dual basis, and redundant representation, and so on. In particular, the redundant representation is attractive since it can simply implement squaring and modular reduction. In this paper, we propose an efficient bit-parallel multiplier for GF(2m) defined by an irreducible all-one polynomial using a redundant representation. We modify the well-known multiplication method which was proposed by Karatsuba to improve the efficiency of the proposed bit-parallel multiplier. As a result, the proposed multiplier has a lower space complexity compared to the previously known multipliers using all-one polynomials. On the other hand, its time complexity is similar to the previously proposed ones.

• Journal of the Korean Society of Industry Convergence
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• v.26 no.6_3
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• pp.1279-1288
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• 2023

Recently, domestic leisure boats have been actively researching eco-friendly product development to enter the global market. Since the hulls of existing leisure boats are mainly made of fiber reinforced plastic (FRP) or aluminum, design techniques for securing structural safety by applying related materials have been mainly studied. In this study, an initial structural design safety assessment of a trimaran pontoon leisure boat with a modular hull structure and eco-friendly high-density polyethylene (HDPE) material was conducted, and sensitivity evaluation and optimization analysis for lightweight design were performed. The initial structural design safety assessment was carried out by creating a finite element analysis model and applying the loading conditions specified in the ship classification regulation to check whether the specified allowable stresses are satisfied. For the sensitivity evaluation, the influence of stress and weight of each hull structural member was evaluated using the orthogonal array design of experiments method, and an approximate model based on the response surface method was generated using the results of the design of experiments. The optimization analysis set the thickness of the hull structural members as the design variable and considered the optimal design formulation to minimize the weight while satisfying the allowable stress. The algorithm of the optimization analysis applied the Gradient-population Based Optimizer (GBO) to improve the accuracy of the optimal solution convergence while reducing the numerical cost. Through this study, the optimal design of a newly developed eco-friendly trimaran pontoon leisure boat with a weight reduction of 10% was presented.

• Steel and Composite Structures
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• v.29 no.3
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• pp.391-404
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• 2018

Researchers have been long studying new building implementation methods to improve the quality of construction, reduce the time of assembly, and increase productivity. One of these methods is the use of modular pre-fabricated structural forms that are composed of a beam, column, short column, pyramidal end block, and connection plates. In this study, a new geometry for the pyramidal end block was proposed that helps facilitate the assembly procedure. Since the proposed configuration affects the performance of this form of connection, its behavior was evaluated using finite element method. For this purpose, the connection was modeled in ABAQUS and then validated by comparing the outputs with experimental results. The research proceeded through analyzing 16 specimens under monotonic and cyclic loading. The results indicated that using the pyramidal end block not only makes the assembly process easier but also reduces the out-of-plane displacement of the short column webs and the vertical displacement of beam end. By choosing appropriate section properties for column and beam, the connection can bear a rotation up to 0.01 radians within its inelastic region and a total of 0.04 radians without any significant reduction in its bearing capacity.