• Journal of the Korea institute for structural maintenance and inspection
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• v.20 no.2
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• pp.74-85
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• 2016

Seismic design of modular structures is usually carried out under the assumption that their load-carrying mechanism is similar to that of traditional steel moment-resisting frames(SMRFs). However, the load carry mechanism of modular structures would be different with that of traditional SMRFs because of their overlapped structural elements and complicated details of connections for the assembly of the unit-modules. In this study, nonlinear static analyses of 3 and 5-story prototype modular structures have been carried out with four different analytical models, which are established in consideration for the effects of overlapped elements and the hysteretic behavior of connections. Prototype structures present different lateral stiffness and strength depending on the modeling of overlapped elements and the rotational behavior of connections. For modular structures designed under assumption that overlapped structural elements are fully composite each other and connections between unit-modules are fixed, their lateral strength and stiffness can be over-estimated. Furthermore, it is known from the analysis results that modular structures with more than 3-stories would possess relatively low overstrength compared to traditional SMRFs.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.33 no.6
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• pp.427-435
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• 2020

Modular structures are relatively lightweight compared to reinforced-concrete or steel structures. However, it is difficult to achieve structural integrity between the columns of unit modules in a modular structure, which causes undesirable effects on the lateral force resistance capacity against wind and earthquake loads. This is more prominent in modular structures whose overall heights are greater. Hence, a post-tensioned modular structural system is proposed herein to improve the lateral force resistance capacity of a typical modular structure. A post-tensioned column-base connection, which is the main component of the proposed modular structural system, is configured with shapes and characteristics that allow inducing self-centering behaviors. Finite element analysis was then performed to investigate the hysteretic behaviors of the post-tensioned column-base connection. The analysis results show that the hysteretic behaviors are significantly affected by the initial tension forces and beam-column connection details at the base.

• 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 Computational Structural Engineering Institute of Korea
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• v.35 no.1
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• pp.15-22
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• 2022

This paper introduces research on the hinge joint of modular structure joints using finite element analysis. The modular structure has a characteristic in that it is difficult to expect the integrity of columns and beams between unit modules because the construction is carried out such that the modules are stacked. However, the current modular design ignores these structural characteristics, considers the moment transmission for the lateral force, and analyzes it in the same manner as the existing steel structure. Moreover, to fasten the moment bonding, bolts are fastened outside and inside the module, resulting in an unreasonable situation in which the finish is added after assembly. To consider the characteristics that are difficult to expect, such as unity, a modular structure system using hinge joints was proposed. This paper proposed and reviewed the basic theory of joints by devising a modified scissors model that is modified from the scissors model used in other research to verify the transmission of load when changing from the existing moment junction to a hinge junction. Based on the basics, the results were verified by comparing them with Midas Gen, a structural analysis program. Additionally, the member strength and usability were reviewed by changing the modular structure designed as a moment joint to a hinge joint.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.18 no.1
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• pp.41-47
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• 2008

This paper presents a new digit level LSB-first multiplier for computing a modular multiplication and a modular squaring simultaneously over finite field GF($2^m$). To derive $L{\times}L$ digit level architecture when digit size is set to L, the previous algorithm is used and index transformation and merging the cell of the architecture are proposed. The proposed architecture can be utilized for the basic architecture for the crypto-processor and it is well suited to VLSI implementation because of its simplicity, regularity, and concurrency.

• Land and Housing Review
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• v.5 no.2
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• pp.81-89
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• 2014

This paper presents various attempts to secure the floor impact sound insulation performance on the dry floor system of steel framed modular house that lately attracted domestic attention. Test results show that in the condition of using dry floor system of D31(D32), the light-weight impact noise performance records the top level in the floor impact sound insulation performance grading system. the heavy-weight floor impact noise performance meets the minimum sound level limit in the floor impact sound insulation performance grading system that enacted regulation on housing construction standards.

• Land and Housing Review
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• v.12 no.3
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• pp.67-78
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• 2021

After World War II, modular housing was developed as a means of quickly and efficiently meeting the housing supply demand. For the past 30 plus years, efforts have been made to improve modular housing in South Korea and to increase their competitiveness in the housing market. This study investigated modular houses based on a steel framed rahem structure which provides a flexible floor plan where walls are easily reconfigured to create rooms of various sizes and functions. Similar to the factory production methods used in the automotive industry, the modular housing industry can also benefit by standardizing such aspects as building components, manufacturing and construction methods, materials, process management, and floor plans. This study examined the feasibility of using a 3m × 3m module for developing various floor plans which are easy to produce and transport. Each 3m × 3m module can be configured to meet different living needs resulting in a complete home when multiple modules are connected. The module configurations can be varied to meet ground transportation and crane limitations. This study found that a 3m × 3m steel framed modular unit is a promising step towards providing residents with plans that meet their living preferences while improving and increasing the supply of modular houses.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2022.04a
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• pp.202-203
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• 2022

In this study, focusing on work types of lifting modules and modules assembly in modular construction sites, unit works were defined according to the construction process of each work type, and safety management elements, safety management activities, and key check point were proposed. The results of this study may have somewhat overlapping contents in the construction procedure in order to derive specific safety management activities and check point for each unit work. Therefore, there is a limit to use the results in an actual modular construction site. In future research, we plan to improve this part and derive a checklist that considers field usability.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2006.11a
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• pp.642-647
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• 2006

Recently Ministry of National Defense is reconstructing old facilities using modular construction method for enhancing soldiers' quality of living. In the future, the use of modular construction method is expected to be increased. But in beginning stage as ROK military facilities that was built by modular was not designed and constructed efficiently, problems for pilot projects need to be analyzed by phases and construction methods should be improved. For the maximized efficiency, design should be made to minimize on-site works, factory automation in an assembly plant should be installed for the better productivity, roads that will be used for transportation should be checked, and joint and connection methods between modules in on-site assembly should be improved for a better quality.

• Journal of IKEEE
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• v.24 no.3
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• pp.901-908
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• 2020

This paper describes a method for scalable hardware implementation of modular inversion. The proposed scalable architecture has a one-dimensional array of processing elements (PEs) that perform arithmetic operations in 32-bit word, and its performance and hardware size can be adjusted depending on the number of PEs used. The hardware operation of the scalable processor for modular inversion was verified by implementing it on Spartan-6 FPGA device. As a result of logic synthesis with a 180-nm CMOS standard cells, the operating frequency was estimated to be in the range of 167 to 131 MHz and the gate counts were in the range of 60,000 to 91,000 gate equivalents when the number of PEs was in the range of 1 to 10. When calculating 256-bit modular inverse, the average performance was 18.7 to 118.2 Mbps, depending on the number of PEs in the range of 1 to 10. Since our scalable architecture for computing modular inversion in GF(p) has the trade-off relationship between performance and hardware complexity depending on the number of PEs used, it can be used to efficiently implement modular inversion processor optimized for performance and hardware complexity required by applications.