• Proceedings of the Korean Institute of Building Construction Conference
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• 2015.11a
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• pp.164-165
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• 2015

Modular construction technique is an adaptation of factory-based mass production concept in ordinary manufacturing industries to construction industry and it assumes that panels, units, etc. are fabricated in factories and assembled in construction sites. Given its structural limitations, modular construction technique is primarily used in low-story buildings whose maximum height is usually five stories, but researchers are actively studying possible adaptation of modular construction technique to high-rise building designs these days as in the case of infill-type modular construction design. Infill-type modular construction technique, most frequently used in high-rise building construction projects, completes frame construction first in reinforced concrete structures and fills unit modules in such structures. However, infill-type modular construction technique leads to longer construction schedule accompanying increase in construction cost, cost overrun due to additional of temporary work, and possible damage to units in the wake of facility construction. Accordingly, this study is performed as a basic study for the development of bottom-up infill-type modular construction technique intended to construct structural frames and fill in units sequentially in a bid to address such drawbacks of current infill-type modular construction technique.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.3C
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• pp.256-262
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• 2002

This paper presents a novel radix-4 modular multiplication algorithm based on the sign estimation technique (3). The sign estimation technique detects the sign of a number represented in the form of a carry-sum pair. It can be implemented with 5-bit carry look-ahead adder. The hardware speed of the cryptosystem is dependent on the performance modular multiplication of large numbers. Our algorithm requires only (n/2+3) clock cycle for n bit modulus in performing modular multiplication. Our algorithm out-performs existing algorithm in terms of required clock cycles by a half, It is efficient for modular exponentiation with large modulus used in RSA cryptosystem. Also, we use high-speed adder (7) instead of CPA (Carry Propagation Adder) for modular multiplication hardware performance in fecal stage of CSA (Carry Save Adder) output. We apply RL (Right-and-Left) binary method for modular exponentiation because the number of clock cycles required to complete the modular exponentiation takes n cycles. Thus, One 1024-bit RSA operation can be done after n(n/2+3) clock cycles.

• Journal of the Korean Society of Industry Convergence
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• v.27 no.2_2
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• pp.403-414
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• 2024

The aim of this study is to evaluate the productivity of multilayered modular housing units during the prefabrication phase. Additionally, it shows the results of productivity analysis conducted using the Web Cyclone technique. Initially, an review of literature and prior studies helped outline the comprehensive manufacturing process of laminated modular apartments, examining the range of minimum, average, and maximum work durations along with workforce size. Subsequently, the productivity of the multilayered apartments' prefabrication was assessed using the Web Cyclone technique, focusing on the workflow, duration, and personnel involved. This analysis also included a comparison of productivity against the initial plan based on the outcomes of a sensitivity analysis.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2012.05a
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• pp.301-302
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• 2012

Recently, high-rise building projects have been in the spotlight in South Korea. Curtain wall construction, as one of important operations in the high-rise building projects is composed of various, entangled and complex unit processes that require a systematic planning to prevent unexpected delays. A schedule simulation technique has been used for deriving more efficient planning and accurate performance measurement. However, the simulation technique has difficulty in collecting actual data and in applying data fluctuations during construction. Thus, this paper suggests a concept model of Modular Simulation Model(MSM) that overcomes such limitations of traditional simulation technique based on curtain wall operations.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2011.05b
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• pp.81-83
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• 2011

A modular house is a house that is assembled on-site from modularized units. As such units are manufactured in a factory, the construction period is reduced, resources are recycled, and quality is improved. However, the construction technique applied to conventional modular houses has not overcome certain structural restrictions, as it is currently used to build houses less than 4 stories in height, which means that it lacks economic feasibility. For this reason, this research aims to develop a scenario of a construction method for Korean modular housing that can be applied to urban-type housing higher than 12 stories. This research is expected to provide fundamental data necessary for the future development of a construction method for Korean modular housing.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2012.05a
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• pp.113-114
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• 2012

The productivity of the construction industry is lower than other industries. Modular system is suggested to enhance the productivity of the construction industry. Modular system is a construction method which installs units manufactured in factory on site. It enables to reduce the duration and improve the quality of the constructions. However, the construction technique applied to modular system has not overcome certain structural problems. To solve the problems and motivate the application of modular system, this study propose the hybrid system which use core to resist a lateral force.

• Journal of KIBIM
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• v.5 no.1
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• pp.1-7
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• 2015

Modular technology has become a major issue of the construction industries to enhance their productivity. Modular bridge construction generally requires the data exchange between the contractors, designers, fabricators and constructors. Therefore, a readily accessible information model interface module based on BIM technology is essential for their communication during a project life-cycle. In this study, BIM based information model interface module for a modular pier was developed. For the information models, the PBS(Product Breakdown Structure) and LOD(Level of Development) were defined. Next, all components of a modular pier were conducted by the parametric modeling technique, and then 3D cell library interface was developed. An nterface module was also developed using VBA(Visua basic Application) for exchanging a data from 3D model library to other softwares such as Microstation, AutoCad and Excel and was connected with MS Access database. The developed information model interface module would improve the design quality of the modular pier and reduce the time and cost for design. Updated 3D information models could be utilized for the fabrication, assembly, and construction process for modular piers.

• International conference on construction engineering and project management
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• 2020.12a
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• pp.278-288
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• 2020

Modular Integrated Construction (MiC) has gained quite momentum as it provides solutions for several problems in the construction sector, particularly in Hong Kong. MiC is converting the building into modules and erecting them easily on site providing various benefits, such as cost and time savings, better quality, lower risk, higher sustainability, less injuries and accidents, etc. The MiC is considered the best alternative to traditional construction approaches in solving the huge housing demand problem in many cities all over the world due to the time-saving privilege. The utilization of MiC is facing a lot of challenges, which are considered obstacles to the wide acceptance of this technique in the construction industry in Hong Kong. This, in turn, has led the interests of the research community to investigate its benefits and challenges aiming at addressing several solutions to harness the benefits of this technique and to tackle these challenges. The present research aims to review the main concept of MiC and to determine the benefits and the challenges of implementing MiC in construction industry. The findings of this research highlight the advantages and limitations of incorporating MiC technique in Hong Kong, which will help the stakeholders to effectively utilize this technique in the construction industry.

• Proceedings of the IEEK Conference
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• 2005.11a
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• pp.813-816
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• 2005

In last several years, the need for the right of privacy and mobile banking has increased. The RSA system is one of the most widely used public key cryptography systems, and its core arithmetic operation IS modular multiplication. P. L. Montgomery proposed a very efficient modular multiplication technique that is well suited to hardware implementation. In this paper, the montgomery modular multiplication algorithms(CIOS, SOS, FIOS) , developed by Cetin Kaya Koc, is presented and implemented using radix-16 and Altera FPGA. Also, we undertake comparisons of power dissipation using Quatrus II PowerPlay Power Analyzer.

• Journal of Institute of Control, Robotics and Systems
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• v.20 no.6
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• pp.625-630
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• 2014

Asynchronous digital circuits working in military and space environments are often subject to the adverse effects of radiation faults. In this paper, we propose a new hardening technique against radiation faults. The considered digital system has the structure of DMR (Double Modular Redundancy), in which two sub-systems conduct the same work simultaneously. Based on the output feedback, the proposed scheme diagnoses occurrences of radiation faults and realizes immediate recovery to the normal behavior by overriding parts of memory bits of the faulty sub-system. As a case study, the proposed control scheme is applied to an asynchronous dual ring counter implemented in VHDL code.