• Korean Journal of Construction Engineering and Management
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• v.22 no.1
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• pp.36-46
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• 2021

With an increasing trend toward high-rise modular construction, the simultaneous use of tower cranes at a modular construction site has recently been observed. Tower crane layout planning (TCLP) has a significant effect on cost, duration, safety and productivity of a project. In a modular construction project, particularly, poor decision about the layout of tower cranes is likely to have negative effects like additional employment of cranes and redesign, which will lead to additional costs and possible delays. It is, therefore, crucial to conduct thorough inspection of field conditions, lifting materials, tower crane capacity to make decisions on the layout of tower cranes. However, several challenges exist in planning for a multi-crane construction site in terms of safety and collaboration, which makes planning with experience and intuition complicated. This paper suggests a multi-objective optimization model for selection of the number of tower cranes, their models and locations, which minimizes cost and conflict. The proposed model contributes to the body of knowledge by showing the feasibility of using multi-objective optimization for TCLP decision-making process with consideration of trade-offs between cost and conflict.

• Proceedings of the Korea Institutes of Information Security and Cryptology Conference
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• 2001.11a
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• pp.289-292
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• 2001

무선인터넷 접속 프로토콜의 사실상 국제표준이라 할 수 있는 WAP 프로토콜의 규격을 제정하는 WAP 포럼에서는 인증서 및 비밀키의 저장, 그리고 암/복호화 및 전자서명/검증 등의 연산을 지원하기 위한 무선인증모듈 규격을 정의하고 있다. 스마트카드로 구현되는 무선인증모듈의 사용 형태를 고려할 때, 다양한 플랫폼에서의 사용과 사용자의 이동성 지원, 그리고 무선인증모듈을 이용한 정보보호 특성 보장은 필수적인 요구조건이다. 본 논문은 무선인증모듈을 스마트카드로 구현함에 있어 멀티 애플리케이션을 지원하고, 기능 확장성을 보장하기 위한 PKCS #15 기반의 무선인증모듈 설계와 구현 결과를 보인다. 본 논문에서는 접촉형 스마트카드에 대한 국제규격인 ISO/IEC 7816 시리즈 규격을 준수한 설계를 보이고, 지수승 모듈러 연산을 하드웨어적으로 지원받아 RSA 1024 비트 암/복호화 및 전자서명/검증을 처리하는 결과를 보인다.

• Proceedings of the Korea Institutes of Information Security and Cryptology Conference
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• 2001.11a
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• pp.302-305
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• 2001

본 논문에서는 셀룰러 오토마타를 이용하여, GF(2$^{m}$ )상에서 A$B^2$ 연산을 m 클럭 사이클만에 처리할 수 있는 새로운 연산기를 설계하였다. 이는 대부분의 공개키 암호화 시스템에서의 기본 연산인 유한 필드 상의 모듈러 지수(modular exponetiation) 연산기 설계에 효율적으로 이용될 수 있다. 또한 셀룰러 오토마타는 간단하고도 규칙적이며, 모듈화 하기 쉽고 계층화 하기 쉬운 구조이므로 VLSI 구현에도 효율적으로 활용될 수 있다.

• KIEAE Journal
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• v.13 no.6
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• pp.121-128
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• 2013

This study attempted to explore the MC design methods of modular construction using discontinuous double module grids and further, the design methods of walls. Modular construction is generally characterized with multiple units called modules with a module dimension of 3M(300mm) appearing in the form of double grids. The discontinuous double grids including correction values and gap values occurs inevitably in the modular construction where units are joined horizontally. Therefore, it is desirable to carry out the MC design taking into account these discontinuous double grids. In this study, the MC design was applied to the plane of wooden houses in modular construction, going through a process of setting the size of pillars and inside dimensions, of determining the dimension of discontinuous double grids that occur during the assembly of units, and of setting the dimension of outer walls in conjunction with the derived dimensions. The dimension of outer walls was applied differently depending on the range of regional use by analyzing the energy performance with the materials used. Consequently, the materials and components of factory-produced buildings can be used directly without processing, and the suitability of the outer wall design can be pre-determined by previewing the calculation of the cross-sectional configuration and heat transmission coefficients of outer walls in modular construction, allowing to be used as a decision-making tool of design.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.17 no.6
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• pp.29-39
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• 2007

RSA is one of the most popular public-key crypto-system in various applications. This paper addresses a high-speed RSA crypto-processor with modified radix-4 modular multiplication algorithm and Chinese Remainder Theorem(CRT) using Carry Save Adder(CSA). Our design takes 0.84M clock cycles for a 1024-bit modular exponentiation and 0.25M cycles for a 512-bit exponentiations. With 0.18um standard cell library, the processor achieves 365Kbps for a 1024-bit exponentiation and 1,233Kbps for two 512-bit exponentiations at a 300MHz clock rate.

• Journal of the Korean Institute of Telematics and Electronics
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• v.22 no.1
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• pp.46-52
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• 1985

The modulo PLL was applied to the implementation of frequency synthesis with the narrow channel spacing, many channels and three different frequency bands. So , VCO (voltage controlled oscillator) designed In this paper is suitable for the device with three different frequency bands 10Hz, 40Hz, 400Hz channel spacing, and 512 channels.

• Proceedings of the Korean Information Science Society Conference
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• 2000.10a
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• pp.605-607
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• 2000

본 논문에서는 유한 필드 GF(2m)상에서 모듈러 곱셈 A(x)B(x) mod p(x)를 수행하는 2-디지트 시리얼 (2-digit-serial) 시스톨릭 어레이 구조인 곱셈기를 제안하였다. LSB-first 곱셈 알고리즘을 분석한 후 2-디지트 시리얼 형태의 자료의존 그래프(data dependency graph, 이하 DG)를 생성하여 시스톨릭 어레이를 설계하였다. 제안한 구조는 정규적이고 서로 반대 방향으로 진행하는 에지들이 없다. 그래서 VLSI 구현에 적합하다. 제안한 2-디지트 시리얼 곱셈기는 비트-패러럴(bit-parallel) 곱셈기 보다는 적은 하드웨어를 사용하며 비트-시리얼(bit-serial) 곱셈기 보다는 빠르다. 본 논문에서 제안한 2-디지트 시리얼 시스톨릭 곱셈기는 기존의 같은 종류의 곱셈기 보다 처리기의 최대 지연 시간이 적다. 그러므로 전체 시스톨릭 곱셈기의 처리시간을 향상시킬 수 있다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2019.05a
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• pp.398-399
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• 2019

This paper presents a method of the circuit design of the multiple-valued digital logic switching functions based on the modular techniques. Fisr of all, we introduce the necessity, background and concepts of the modular design techniques for the digital logic systems. Next, we discuss the definitions that are used in this paper. For the purpose of the circuit design for the multiple-valued digital logic switching functions, we discuss the extraction of the partition functions. Also we describe the construction method of the building block, that is called the modules, based on each partition functions. And we apply the proposed method to the example, we compare the results with the results of the earlier methods. In result, we decrease the control functions, it means that we obtain the effective cost in the digital logic design for any other earlier methods. In the future research, we require the universal module that traet more partition functions and more compact module.

• Journal of the Architectural Institute of Korea Structure & Construction
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• v.33 no.12
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• pp.37-44
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• 2017

Due to structural characteristics, construction costs and duration of a modular system would be saved by minimizing the schedule on the job site. As such, it is crucial to develop a connection that can guarantee stiffness while allowing for simple assembling. Particularly, the mid- to high-rise construction of the modular system necessitates the securing of the structural stability and seismic performance of multi-unit frames and connections, and thus, the stiffness of unit-assembled structures needs to be re-evaluated and designed. However, evaluating a frame consisting of slender members and reinforcing materials is a complicated process. Therefore, the present study aims to examine the structural characteristics of a modular unit connection based a method for reinforcing connection brackets and hinges while minimizing the loss of the cross section. Toward this end, the study modeled the beam-to-column connection of a modular system with the proposed connection, and produced a specimen which was used to perform a cycling loading test. The study compared the initial stiffness, the attributes of the hysteretic behavior, and the maximum flexural moment, and observed whether the model acquired the seismic performance, compared to the flexural strength of the steel moment frame connection that is required by the Korean Building Code. The test results showed that the proposed connection produced a similar initial stiffness value to that of the theoretical equation, and its maximum strength exceeded the theoretical strength. Furthermore, the model with a larger ceiling bracket showed higher seismic performance, which was further increased by the reinforcement of the plate.

• Journal of the Architectural Institute of Korea Structure & Construction
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• v.34 no.3
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• pp.19-28
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• 2018

Key factors that ensure competitiveness of modular unit include consistent high quality and connection condition that ensures high structural performance while minimizing the overall scale of the on-site process. However, it is difficult to evaluate the structural performance of the connection of modular unit, and its structural analysis and design method can be different depending on the connection to its development, which affects the seismic performance of its final design. In particular, securing the seismic performance is the key to designing modular systems of mid-to-high-rise structure. In this paper, therefore, the seismic performance of the modular system with bracket-typed fully restrained moment connections according to stiffness and the shapes of various connection members was evaluated through experimental and analytical methods. To verify the seismic performance, a cyclic loading test of the connection joint of the proposed modular system was conducted. As a result of this study, theoretical values and experimental results were compared with the initial stiffness, hysteresis behavior and maximum bending moment of the modular system. Also, the connection joint was modeled, using the commercial program ANSYS, which was then followed by finite element analysis of the system. According to the results of the experiment, the maximum resisting force of the proposed connection exceeded the theoretical parameters, which indicated that a rigid joint structural performance could be secured. These results almost satisfied the criteria for connection bending strength of special moment frame listed on KBC2016.