• 한국정보과학회논문지:시스템및이론
• /
• 제26권7호
• /
• pp.743-751
• /
• 1999

공개키 암호 시스템에서 모듈러 지수 연산은 주된 연산으로, 이 연산은 내부적으로 모듈러 곱셈을 반복적으로 수행함으로써 계산된다. 본 논문에서는 GF(2m)상에서 수행할 수 있는 Montgomery 알고리즘을 분석하여 right-to-left 방식의 모듈러 지수 연산에서 공통으로 계산 가능한 부분을 이용하여 모듈러 제곱과 모듈러 곱셈을 동시에 수행하는 선형 시스톨릭 어레이를 설계한다. 본 논문에서 설계한 시스톨릭 어레이는 기존의 곱셈기보다 모듈러 지수 연산시 약 0.67배 처리속도 향상을 가진다. 그리고, VLSI 칩과 같은 하드웨어로 구현함으로써 IC 카드에 이용될 수 있다.Abstract One of the main operations for the public key cryptographic system is the modular exponentiation, it is computed by performing the repetitive modular multiplications. In this paper, we analyze Montgomery's algorithm and design a linear systolic array to perform modular multiplication and modular squaring simultaneously. It is done by using common-multiplicand modular multiplication in the right-to-left modular exponentiation over GF(2m). The systolic array presented in this paper improves about 0.67 times than existing multipliers for performing the modular exponentiation. It could be designed on VLSI hardware and used in IC cards.

• Advances in concrete construction
• /
• 제15권6호
• /
• pp.377-389
• /
• 2023

In this study, an improved modular arch system with the lower arch space composed of a precast arch block and an outrigger was proposed as an underground culvert, and its applicability and structural behaviors were confirmed. This modular arch culvert structure with vertical walls was designed using precast blocks and by adjusting the placement spacing of concrete blocks to the upper part form an arch shape and the lower part form a vertical wall shape, based on previously researched modular arch systems. Owing to the vertical wall of the proposed modular arch system, it is possible to secure a load-carrying capacity and an arch space that can sufficiently resist the earth pressure generated from the backfill soil and loading on the arch system. To verify the structural characteristics, and applicability of the proposed modular precast arch culvert structure, a full-scale modular culvert specimen was fabricated, and a loading test was conducted. By examining its construction process and loading test results, the applicability and constructability of the proposed structure were analyzed along with its structural characteristics. In addition, its the structural predictability and safety for the applicability were evaluated by comparing the construction process and loading test results with the FE analysis results.

• 한국건축시공학회:학술대회논문집
• /
• 한국건축시공학회 2021년도 봄 학술논문 발표대회
• /
• pp.291-292
• /
• 2021

In modular construction, it is insufficient for safety management of workers, and workers are still exposed to the risk of accidents due to work at high places for lifting and assembly work in modular construction sites. Therefore, it is necessary when preventive safety management through risk management of workers on modular construction sites. This study is a basic study for the risk assessment(checklist) of modular construction, and the purpose of this study is to analyze the risk factors of the module lifting work at the modular construction site. It is intended to identify the hazard risk factors and improvement measures of the existing lifting operation, by analyzing the case of the risk assessment of the existing RC method, and to identify the risk factors for each work process when lifting the module. In the future, the results of this study are expected to be utilized in the development of checklists for risk assessment as safety management plan for modular construction sites.

• 국제학술발표논문집
• /
• The 9th International Conference on Construction Engineering and Project Management
• /
• pp.571-578
• /
• 2022

Modularization in a high-rise building is different from a small building, as it is exposed to more lateral forces like wind and earthquakes. The integrity, robustness, and overall stability of the modules and their performance is based on the joining techniques and strong structural systems. High lateral stiff construction structures like concrete shear walls and frames, braced steel frames, and steel moment frames are used for the stability of high-rise modular buildings. Similarly, high-rise stick-built buildings have concrete cores and perimeter frames for lateral load strength and stiffness. Methods for general steel-concrete connections are available in many works of literature. However, there are few modular-related papers describing this connection system in modular buildings. This paper aims to review the various research and practice adopted for steel-to-concrete connections in construction and compare the methods between stick-built buildings and modular buildings. The literature review shows that the practice of steel module-to-concrete core connection in high-rise modular buildings is like outrigger beams-to-concrete core connection in stick-built framed buildings. This paper concludes that further studies are needed in developing proper guidelines for a steel module-to-concrete core connection system in high-rise modular buildings.

• 한국건설관리학회논문집
• /
• 제19권6호
• /
• pp.124-134
• /
• 2018

모듈러 주택은 많은 장점이 있음에도 불구하고, RC구조에 익숙한 소비자들의 모듈러 주택에 대한 낮은 선호도가 모듈러 주택의 높은 공사비를 초래하고 있다. 모듈러 건축물의 공사비는 RC 구조 대비 130% 전후로 형성되어 있어 모듈러 건축물의 경제성 확보가 시급하다. 따라서 본 연구에서는 모듈러 주택의 공종별 절감가능 금액을 산출한 후, 장기적 관점에서의 경제성 분석을 진행하였다. 연구 진행을 위해 모듈러 주택의 내역서를 공장제작분 및 현장설치분으로 분개하여 공종별 발생하는 재료비, 노무비, 경비를 비교 분석을 진행했다. 그 후 파레토도를 작성하여 비용 누계 80% 내외에 포함되는 핵심 공종을 찾아 공사비 절감 가능대상으로 선정하였다. 국내 모듈러 건축의 시장규모가 일본, 유럽 국가 등 모듈러 선진국 수준과 비슷하다는 가정하에 전문가 인터뷰를 통해 모듈러 공법의 특성을 반영한 비용절감 방법을 설정하였고, 모듈러 업체 전문가를 대상으로 한 설문조사를 통해 비용절감 방법을 적용했을 때의 공종별 절감 가능 금액을 산출하고, 총 절감가능 금액을 산출했다. 비용절감 방법 중 '자동화 및 기계화'방법을 적용했을 때의 절감가능성이 1.54%로 가장 큰 것을 알 수 있었고, 국내 모듈러 생산 과정이 전자동화 및 기계화가 된다면 공사비 절감 뿐만 아니라 공기 단축도 기대해 볼 수 있다고 판단한다.

• 한국전산구조공학회논문집
• /
• 제33권6호
• /
• pp.427-435
• /
• 2020

모듈러 건축물은 철근콘크리트 및 철골 구조물에 비하여 상대적으로 경량이고, 단위 모듈간 기둥의 일체성을 기대하기 어려운 구조적 특성을 가진다. 이와 같은 구조적 특성은 모듈러 건축물의 높이가 높아짐에 따라 바람 및 지진과 같은 횡력저항성능에 직접적인 영향을 미친다. 본 연구에서는 횡력저항성능을 향상시키기 위해 긴장재를 활용한 모듈러 구조시스템을 제안하였다. 모듈러 구조시스템을 구성하는 주요 요소인 포스트텐션 기둥-바닥 접합부는 셀프 센터링 거동을 유도하기 위한 형상 및 상세를 가진다. 포스트텐션 기둥-바닥 접합부의 이력 거동을 상세히 파악하기 위해 유한요소해석을 수행하였으며, 그 결과 초기 긴장력 및 보-기둥 접합부의 접합 조건에 따라 이력 거동은 확연한 차이를 보이는 것으로 나타났다.

• Ocean Systems Engineering
• /
• 제14권3호
• /
• pp.277-299
• /
• 2024

In this study, the wave-induced motion responses of modular floating structures (MFS) was investigated through a series of experiments in a two-dimensional wave tank. A 1:63 scale model test was conducted using a 1-by-2 modular floating structure consisting of two modules and connectors. Two different types of connectors were considered: a pitch-free hinge and rigid connector. The numerical analysis was performed based on the higher-order boundary element method (HOBEM) and wave Green function with potential flow theory. First, the heave and pitch RAOs of the modules from the regular wave tests were directly compared with numerical analysis results. Next, the motion spectra and their statistical values from the irregular wave tests were compared with the numerical analysis results. The study revealed that the sheltering effect of the weather side module led to a reduction in motion of the lee side module. The numerical analysis showed good agreement with the experimental data, demonstrating the validity of the numerical method. Additionally, the rigid connector, which strongly constrain all six degrees of freedom, significantly reduce pitch motion, making the modules behave as a single rigid body.

• 한국소성가공학회:학술대회논문집
• /
• 한국소성가공학회 1994년도 추계학술대회 논문집
• /
• pp.64-73
• /
• 1994

An updated Lagrangian finite element analysis with automatic remeshing scheme is applied to the three-dimensional hot extrusion through landless square dies. In the remeshing procedure, it is very difficult that the meshes are generated automatically with consideration of physical characteristics. In the presented study, the mesh generation is accomplished by modular concept. The generated meshes by modular concept have advantages, especially for three-dimensional problems, such as economized computational time and consideration of physical characteristic. In the problem, orifice shapes of square die are divided into two for the extrusion of solid sections. The orifice adaptive modules are developed for each type and the numerical examples are carried out for each type.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2001년도 추계학술대회 논문집
• /
• pp.247-252
• /
• 2001

In this study, an aluminum electric motor car with a modular front end made of composite materials is numerically evaluated applying the standard specifications for the urban EMU(Electric Multiple Unit) train. Structural analyses under compressive load, torsional load and free vibration satisfy the standard specifications, but analysis under normal load doesn't. By the way, the aluminum bodyshell of the car except the modular front end is almost same to that of the Korean standard EMU, which satisfy the standard specifications. It is presumed that the stiffness of the modular front end made of composite materials haves some influence on the strength of the aluminum bodyshell.

• 한국철도학회논문집
• /
• 제6권4호
• /
• pp.273-278
• /
• 2003

In this study, an aluminum bodyshell with a modular front end made of composite materials is numerically evaluated applying the standard specifications for the urban EMU (Electric Multiple Unit) train. Structural analyses under compressive load, torsional load and free vibration satisfy the standard specifications, but analysis under normal load doesn't. By the way, the aluminum bodyshell of the car except the modular front end is almost same to that of the Korean standard EMU, which satisfy the standard specifications. It is presumed that the stiffness of the modular front end made of composite materials has some influence on the strength of the aluminum bodyshell.