• Journal of Korea Multimedia Society
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• v.20 no.2
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• pp.289-297
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• 2017

When implementing a hardware elliptic curve cryptosystem (ECC) module, the efficient design of Modular Inverse (MI) algorithm is especially important since it requires much more computation than other finite field operations in ECC. Among the MI algorithms, binary Right-Shift modular inverse (RS) algorithm has good performance when implemented in hardware, but Montgomery Modular Inverse (MMI) algorithm is not considered in [1, 2]. Since MMI has a similar structure to that of RS, we show that the area-improvement idea that is applied to RS is applicable to MMI, and that we can improve the speed of MMI. We designed area- and speed-improved MMI variants as hardware modules and analyzed their performance.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2016.05a
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• pp.19-20
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• 2016

Domestic construction industry has experienced many difficulties as it has been on a downward. It's a way that active modular structure market to solve this problem. However, as Modular structure technical standard in Korea is in the early stages, our modular factory maufactured rate is almost 40% lower than overseas. Besides, there is less design diversity so it just applies for a few buildings like low-rise building and general group barrackes. To deal with these problems, it is essential to modulating the equipment which can improve the production rate. This will help to ensure the quality, shortening of the construction period, the reduction of labor costs. We have defined the name of segmented by each installation location of the equipment to modulating equipment. And it was examined the suitability of the modulating of the location-specific utility system. The results of the analysis are discussed on the page.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.12 no.1
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• pp.136-142
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• 2001

In this paper, a method of canceling and suppressing differential mode crosstalk noise signals caused by non-uniform coupling between two transmission lines in UTP (unshielded twisted pair) modular jacks is discussed. Differential mode crosstalk noise signals in balanced transmission lines with UTP modular jacks were suppressed, by applying field cancellation techniques to this modular jack. To verify an effectiveness of the field cancellation techniques, 8 pin modular jacks were made, and the NEXT (Near End Crosstalk) losses were measured to prove its applicability by the network analyzer(HP8720C) at 100 Mb/s.

• Proceedings of the KIPE Conference
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• 2010.11a
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• pp.44-45
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• 2010

In this paper a new PFC Controller for 3-Phase Modular UPS is proposed. The PFC circuit for 3-Phase Modular UPS is implemented using three 1-phase 3-level boost PFC circuits. To control DC output voltage and AC input current, single voltage controller considering imbalance of two capacitor voltages and three independent current controllers are used in proposed PFC controller.

• Journal of the Regional Association of Architectural Institute of Korea
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• v.21 no.5
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• pp.133-140
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• 2019

Building Information Modeling (BIM) and modular construction are regarded as important technologies that could contribute to overcoming the crisis faced by the construction industry. However, BIM uptake in current modular construction projects is limited. Moreover, there are no specific guidelines to support decision-making regarding the application of BIM in modular construction projects. Therefore, this study aims to analyze the possibility for BIM uptake in each phase of modular construction projects in Korea. Initially, the literature detailing on BIM uptake cases in modular construction projects was reviewed. The detailed work and activities for each phase of a modular project were analyzed via a questionnaire targeting domestic modular experts, to derive items requiring improvement due to errors or changes occurring in the actual project. Ten realistic BIM uptake items were derived, reflecting the results of literature review and expert interviews. Then, the BIM uptake items in each phase were analyzed in terms of necessity and efficiency via a second questionnaire using five-point Likert scales. Finally, the BIM utilization index (BIM UI) of the BIM uptake items was suggested as a priority measure. As a result, the BIM UI of "3D coordination" (U2), "design authoring and reviews for off-site fabrication" (U3), and "detailed 3D modeling for off-site fabrication" (U4), were assigned the highest priority. The results of this study can be used as guidelines to support decision-making regarding the application of BIM in modular construction projects.

• Korean Journal of Construction Engineering and Management
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• v.15 no.1
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• pp.101-110
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• 2014

The ministry of Land, Infrastructure and Transport announced that they launched the pilot project to offer Happy House built with modular construction as part of the major projects of incumbent government in 2013. The market size of modular construction is getting increasingly enlarged together with strong will of government. The major challenges that current modular construction encounters can be summed up as lack of standardization of material on the stage of design and fabrication. The portion of material costs in modular construction marks 16 to 17% higher than the existing other construction method, and account for 60 % of total construction cost, which is why material management is the most important factor. However, the imperfect standardization and specification on design causes high loss of materials on fabrication, which makes the construction wastes and total construction cost increasing in accordance with the increase of material costs. This study has been conducted to verify major modules by developing optimization algorithm on gypsum board material among wall finishing materials. It is expected that this paper contributes not only to eco-friendly construction by minimizing the waste factors of materials through these efforts, but also to removing high cost issues which had been recognized as a setback of current modular construction.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.38 no.12
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• pp.1209-1216
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• 2010

This paper dealt with an alternative for maximizing mass savings in spacecraft design by replacing conventional aluminum alloy housing used for various spacecraft avionics by composite materials. Key requirements were defined for the purpose of composite housing design with sufficient durability and various functionalities as well as more lightweight characteristics as compared with aluminum alloy widely-used for conventional electronics housing. Conceptual design was also carried out for manufacturing modular, lightweight composite electronic housing equipped with high thermal and electrical conductivities, EMI protection, and radiation shielding characteristics as well as excellent structural performance; feasibility of enhancing mass savings in spacecraft design was presented.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.38 no.6
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• pp.620-628
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• 2010

Small satellites can be used for various space research and scientific or educational purposes due to advantages in small size, low-cost, and rapid development. Small Satellites have many advantages of application to Responsive Space. Compared to traditional larger satellites, however, Small satellites have many constraints due to limitations in size. Therefore, it is difficult to expect high performance. To approach maximum capability with minimal size, weight, and cost, standard modular platform of Small satellites is necessary. Modularity supports plug-and-play architecture. The result is Small satellites that can be combined quickly and reliably using plug-and-play mechanisms. For communication between modules, standard bus interface is needed. Controller Area Network(CAN) protocol is considered optimum data bus for modular Small satellite. CAN can be applied to data communication with high reliability. Hence, design optimization and simplification can also be expected. For ease of assembly and integration, modular design can be considered. This paper proposes development method for standardized modular Small satellites, and describes design of data interface based on CAN and a method of testing for modularity.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.35 no.9
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• pp.816-825
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• 2007

With a view to building up a program used in conceptual design of liquid rocket engine system, a preliminary performance-based code for an integrated engine system has been developed by incorporating sub-modular programs for each essential engine component. Modular descriptions for each component were formulated mathematically with essential parameters. In the whole iterative circuits for predicting engine performance, matching conditions of mass flow rate and pressure drop through each engine component have been considered. Mass balance calculations at each inter-component boundary are found smoothly converged. All the pressure drops through engine components as a function of mass flow rate are added up to provide turbo-pump outlet condition. In this paper, the flow chart for each iterative circuit and design methodologies are presented. Resultant predictions are validated with real engine data.

• 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.