• Journal of the Korea Institute of Building Construction
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• v.18 no.3
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• pp.277-283
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• 2018

This study is conducted to improve the manufacturing process of the modular construction method, which is a pre-fabricated construction method recognized for its advantage on the shortening of construction time. This study first identified the factors that result in shortening of pre-fabrication processes in the current module-processing factory. In addition, those identified factors were further considered for installing the M.E.P. system that is being outsourced on the main module in the production line. A manufacturing process of the construction modules, which considers installation of a M.E.P. system most suitable for shortening the time on the outsourcing of modular construction, is introduced throughout the research. Furthermore, this study suggests the factors in need of improvement during design phase of modular construction and improvement measures to consider the quality of unit modules by focusing on the module parts that are most exposed to defects.

• Korean Journal of Construction Engineering and Management
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• v.17 no.6
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• pp.3-12
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• 2016

The purpose of this study is to provide a domestic applicable modular building construction process by benchmarking international best practices. In this study, we derive the risk factors that may occur in performing a modular construction projects and the modular construction management factors through case analysis. In order to effectively respond to risks in performing a modular building projects, we propose the modular building construction process which is separated by a transportation, lifting, assembly steps based on the unit module construction sequence. It is the key to providing management information and guidelines for the design, production, construction participants by reflecting the information for each step in the process. This study would prevent a potential hazard which may occur in the construction process. Consequently, It could result in saving the entire cost of modular construction project as shortening the project schedule and could improve workability of modular construction.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.27 no.6
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• pp.663-672
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• 2014

Recently, modular structural systems have been applicable to building construction since they can significantly reduce building construction time. They consists of several unit modular frames of which each beam-column joint employs an access hole for connecting unit modular frames. Their structural design is usually carried out under the assumption that their load-carrying mechanism is similar to that of a traditional steel moment-resisting system. In order to obtain the validation of this assumption, the cyclic characteristics of beam-column joints in a unit modular frame should be investigate. This study carried out finite element analyses(FEM) of unit modular frames to investigate the cyclic behavior of beam-column joints with the structural influence of access holes. Analysis results show that the unit modular frames present stable cyclic response with large deformation capacities and their joints are classified into partial moment connections. Also, this study develops a simple spring model for earthquake nonlinear analyses and suggests the Ramberg-Osgood hysteretic rule to capture the cyclic response of unit modular frames.

• Journal of IKEEE
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• v.24 no.4
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• pp.961-968
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• 2020

This paper describes a design of high performance modular multiplier that is essentially used for elliptic curve cryptography. Our modular multiplier supports modular multiplications for five field sizes over GF(p), including 192, 224, 256, 384 and 521 bits as defined in NIST FIPS 186-2, and it calculates modular multiplication in two steps with integer multiplication and reduction. The Karatsuba-Ofman multiplication algorithm was used for fast integer multiplication, and the Lazy reduction algorithm was adopted for reduction operation. In addition, the Nikhilam division algorithm was used for the division operation included in the Lazy reduction. The division operation is performed only once for a given modulo value, and it was designed to skip division operation when continuous modular multiplications with the same modulo value are calculated. It was estimated that our modular multiplier can perform 6.4 million modular multiplications per second when operating at a clock frequency of 32 MHz. It occupied 456,400 gate equivalents (GEs), and the estimated clock frequency was 67 MHz when synthesized with a 180-nm CMOS cell library.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2012.05a
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• pp.765-766
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• 2012

• Journal of the Korea Furniture Society
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• v.21 no.5
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• pp.380-391
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• 2010

Modular furniture's colors, materials, finishing materials and quantities are determined by users' tastes and it's diverse functions, shapes and sizes are determined by the spaces of users. That is, modules satisfy the diversity of consumers, meet differentiated individuals' tastes and enable communications with consumers rather than delivering one-way messages of designers. The contemporary spaces of the 21st century have been gradually shifting from uniform spaces attaching weight on individuals' individuality and tastes and along with it, the consumption of expensive custom-made furniture and foreign branded furniture is increasing to satisfy those small numbers of consumers who want to express diversified individuality. The modular furniture as a concept which is the most suitable to Mass Customization can be produced in large quantities while considering the diverse needs and tastes of individuals and it does not have absolute shapes or sizes. The concept of modular furniture shows similarities to the creation of fractals that forms shapes by self similarities, repeats and similar transformations which is in the same context as the characteristics of a modular design that presents diversity with scales, materials and jointing points. Fractals will be combined with the digital media of today to present great plasticity and influence designers more heavily. Pursuit of new modeling is a requisite for the creation of future spaces and it will require continuous creativity and the transformable modular furniture will contribute to the satisfaction of diverse consumers' needs. This study is to propose the modular furniture that considers the diversity of the public in the 21st century and their individuality and that will enable interactions between designers and consumers.

• Journal of Korean Society of Steel Construction
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• v.19 no.3
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• pp.323-333
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• 2007

This paper presents a study that attempted to improve the site applicability of profile sheets and check the effects of bending reinforcement in composite profiled beams, and consequently, to suggest an improved modular-type CB2 and two types of bending reinforcement methods. As a result of the reinforcing and reforming modular profiled beam experiment conducted, CBIIshowed an adequate deformation capacity as well as a sufficient plastic plateau at the maximum load and thereafter. For all the specimens, an insignificant modular slip occurred while linear relations were kept constant, at up to approximately 50% of the maximum load and at constant linear relations. The experimental values were very low. Probably, due to the small-scale experiment, the area of the concrete for the concrete filling and covering might have been insufficient, which might have led to the failure to improve the strength. Comparing the results with the standard design stress, all the specimens-except for T16 and B16-indicated more than 0.9. Based on the standard design stress, the reinforced modular profiled beam was consideredto have positive applicability.

• Journal of Convergence for Information Technology
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• v.7 no.5
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• pp.95-102
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• 2017

Modular toys for creative education require functional blocks to create various types of movements. An active drive module and a lot of passive connection blocks are needed to express motion with combination. In this paper, we propose the design of modular toys to produce various creative movements and controller structure working with them. In order to facilitate the connection between the designed modules, a connection method and a suitable mechanism are suggested. We also dealt with the design of various types of sensor modules that can work in conjunction with modular toys. Using these toys, typical standard application form that can be imitated educationally is suggested and showed the usefulness of the modular toy by actually applying it with designed modules and components. The proposed method is applied to actual educational toys, and the operation is effectively performed by recording operation and playing repetitive operation.

• Journal of the Architectural Institute of Korea Structure & Construction
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• v.34 no.4
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• pp.25-33
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• 2018

In regard to modular systems, new methods, as well as middle and high-story unit design ideas, are currently being studied. These studies need to focus on the enhanced stiffness and seismic performance of these connections, and see that the development of fully restrained moment connections can improve the seismic performance. For this reason, this study evaluates the performance of the connections of the ceiling bracket-typed modular system through repeated loading tests and analyses. In order to compare them with these modular units, new unit specimens with the bracket connection being different from that of the traditional modular unit specimens were designed, and the results of repeated loading tests were analyzed. In the traditional units, the structural performances of both welding connection and bolt connection were evaluated. In regard to the testing results, the initial stiffness of the hysteresis curve was compared with the theoretical initial stiffness, and the features of all specimens were also analyzed with regard to the maximum moment. In addition, the test results were examined with regard to the connection flexural strength of the steel special moment frame specified under the construction criteria KBC2016. The connections, which were proposed in the test results, were found to be fully restrained moment connections for designing strong column-weak beams and meeting the requirements of seismic performance of special moment frames.

• Nuclear Engineering and Technology
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• v.52 no.12
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• pp.2789-2802
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• 2020

Small Modular Reactors (SMRs) are attracting wide attention due to their outstanding performance, extensive studies have been carried out for lead-based fast reactors (LFRs) that cooled with Lead or Lead-bismuth (LBE), and small modular natural circulation LFR is one of the promising candidates for SMRs and LFRs development. One of the challenges for the design small modular natural circulation LFR is to master the natural circulation thermal-hydraulic performance in the reactor primary circuit, while the natural circulation characteristics is a coupled thermal-hydraulic problem of the core thermal power, the primary loop layout and the operating state of secondary cooling system etc. Thus, accurate predicting the natural circulation LFRs thermal-hydraulic features are highly required for conducting reactor operating condition evaluate and Thermal hydraulic design optimization. In this study, a thermal-hydraulic analysis code is developed for small modular natural circulation LFRs, which is based on several mathematical models for natural circulation originally. A small modular natural circulation LBE cooled fast reactor named URANUS developed by Korea is chosen to assess the code's capability. Comparisons are performed to demonstrate the accuracy of the code by the calculation results of MARS, and the key thermal-hydraulic parameters agree fairly well with the MARS ones. As a typical application case, steady-state analyses were conducted to have an assessment of thermal-hydraulic behavior under nominal condition, and several parameters affecting natural circulation were evaluated. What's more, two characteristics parameters that used to analyze natural circulation LFRs natural circulation capacity were established. The analyses show that the core thermal power, thermal center difference and flow resistance is the main factors affecting the reactor natural circulation. Improving the core thermal power, increasing the thermal center difference and decreasing the flow resistance can significantly increase the reactor mass flow rate. Characteristics parameters can be used to quickly evaluate the natural circulation capacity of natural circulation LFR under normal operating conditions.